Twilight Sparkle and Rainbow Dash hurried back to the laboratory. The others stood huddled around Fluttershy, who was speaking in soft, excited tones. “Girls, we need to go out and find River. She’s left the castle for some reason,” Twilight burst out, worry tugging at her stomach.

Applejack leaned around Fluttershy, looking concerned. “That shore sounds suspicious, Twalight. You’re sure she ain’t just wandered off to another part of the castle?”

“Yes. That guiding spell I gave her is also supposed to track her and keep me updated on her location.” The purple alicorn scowled as everypony gave her identical looks of surprise. “What? I’m not that oblivious! I knew there was a risk she wasn’t completely above board.” Twilight sighed, wings wilting at her sides. “I really hoped she was, though. She sounded so sincere…”

“Well, don’t give up yet, Twilight!” Pinkie Pie sang, bouncing over to her friend. “There could tooootally be another explanation! Like maybe she realized that something important from back home came through with her and she’s off to find it so it doesn’t get lost in our world forever!”

Rainbow Dash did an upside-down loop overhead, squinting doubtfully. “I dunno, maybe. She did sound pretty legit. And I was really looking forward to fighting some crazy monsters from another dimension.”

Twilight shook her head, lips pursed in thought. “I hope so. It’s either that, or she was sent to spy specifically on how my mirror spell works. That doesn’t explain the odd readings I was getting, though—”

She had been reaching her hoof towards the Dimensional Cross-Particle Energy Reader as she spoke, not noticing how it was vibrating visibly. As soon as Twilight touched it with her hoof, it gave off a deafening trumpet sound. Everypony flung their hooves to their ears in pain.

“What?” Twilight stared at the device in shock. The earbleedingly loud trumpet toots continued as Twilight twiddled with her device, yelling to be heard. “I don’t believe it! This is looking promising, girls! That sound means the Energy Reader has confirmed that a significant number of cross-dimensional photons are irradiating this area from a recently present source!”

“WHAT DOES THAT MEAN?” Rarity shouted back. “AND COULD YOU PLEASE BE A DEAR AND TURN THAT OFF?”

The noise cut out with a sad toodle as Twilight finished typing something into the front interface. She stood grinning hugely at her deafened friends. “It means,” she said triumphantly, “that one way or another, River is definitely from some other world!

There were a few relieved and understanding nods. Then a quiet, rather puzzled voice spoke up.

“That sounds nice. Um, what are we talking about?”

Fluttershy stood in the center of the group, wearing the most polite look of complete confusion every invented. Everypony exchanged embarrassed grins. “Sorry, Fluttershy, you missed quite a bit while you were out,” Rarity offered. “Suffice it to say that Twilight has had a rather interesting visitor, who may in fact be from another world entirely. She’s gone missing, though, and we aren’t at all sure why.”

“Where were you, anyway?” Rainbow Dash demanded, folding her hooves. “I looked all over for you before flying over here to catch up with the others!”

“Oh! Well, you see, I was out walking and I ran into just the most adorable little—“

“No time for that now,” Twilight declared. “Sorry, Fluttershy, but you’ll have to tell us later. We need to track down River. I don’t know why she’s run off, but if she is a visitor from another world, I need her here to find out why her dimensional particles are sending me such mixed signals. Plus we can’t just have her wandering around town. Who knows what kinds of problems could come up if we leave a visitor from another dimension wandering willy-nilly around Ponyville?”

“Yeah,” Spike said thoughtfully, tapping a claw on his chin, “I can’t imagine what kinds of crazy antics that could cause.” He met Twilight’s suspicious glare with the innocence of a baby angel.

“Well, then, let’s get to it!” Applejack said, stepping forward with a face full of determination. “You said you can track her, Twi?”

In answer, Twilight Sparkle revved up the magic in her horn. Carefully forming the spell in her mind, she cast it, and a larger, brighter purple sphere of light appeared in the air. She pointed at it, then out the door. “Applejack, Rarity, and Rainbow Dash, you all follow this sphere; it’ll lead you towards the one that I linked to River. Hopefully she was right, and nothing dangerous has followed her through whatever portal she came through into this world; but you can contact me with that sphere if anything comes up!” Twilight was already at the mirror machine, punching data into a panel at its side as she continued. “Fluttershy, you stay with me so I can catch you up on what’s going on and because I could use the extra sets of hooves. And I’ll work on calibrating the mirror to lock onto the energy readings I gathered with my Energy Reader. If all goes well, we could have this portal ready to go by sunset!”

“So what I’m hearin’ is, we should tryta get her back here afore the sun goes down.” Applejack tipped her hat. “We’re on it, Twalight!”

“Whoopee!” Pinkie Pie was already bouncing out the door after the purple sphere. “Let’s get Ponyville’s first pony/human hide-and-seek party on the road!”

-----

The Lord of Chaos was not having a good day. Discord reappeared in his home dimension and stormed (with literal storm clouds) back into his house, walking through the closed door and slamming it open violently behind him. With a growl, he sat on the empty air next to his recliner and kicked back, conjuring up a viewing ball so he could start trying to salvage this mess.

Of all of the inter-dimensional travelers he’s encountered/made, this one was by far the brattiest, no two ways about it. Threatening to tell on him to Twilight, as if he’d actually done something wrong! There were no rules in any universe against transporting a person unexpectedly to a neighboring universe that he was aware of (except for that one with the ducks, but he avoided that place on principle).

“Still,” he muttered begrudgingly, “Twilight does have a way of blowing everything out of proportion.” He should have just left the obstinate little twerp to Twilight Sparkle’s ecstatically happy foray into magical science for a few days, but the idea of things being so easy for his newest project was simply unbearable. Only now he’d have his hands full keeping her away from Twilight and the gang so she wouldn’t blab about his admittedly poorly-advised revelation concerning his involvement in the whole affair. It wasn’t like he could just send her back, after all.

Discord spun the glowing ball on his palm, turning the viewscreen to look around Ponyville Square. Yep, there was the little black nuisance, running in a panic to try and find her lost Chewie. That had been a stroke of genius on his part, but Twilight and the others would no doubt go searching for their precious interdimensional visitor, and if little miss River Tattle gave up the search too quickly and returned to the castle, he’d be back where he’d started….

The search. “Of course!” Discord exclaimed, an actual lightbulb appearing above his head as the pieces of an idea fell into place. With a snap, he made the viewing spell vanish, and stood from his invisible recliner with a stretch of his serpentine spine. “I don’t know why I ever bother doubting myself,” he said with a chuckle, and, closing the door again, he walked through it and back out into normal time and space.

----

The ponies of Ponyville had, it went without saying, gotten used to extremely weird things interrupting their daily lives. It was almost a sport for some, guessing what kind of catastrophe was going to strike next, and when. (The boys on the bowling team were betting hard on a pack of timberwolves let by an evil unicorn mage from the Everfree Forest, no later than March.) So when a frazzled and unfamiliar (but still perfectly normal-looking) unicorn went galloping through town square early that morning, disappeared into Twilight’s castle, and then came galloping back a few hours later looking equally frazzled but less unfamiliar and now accompanied by a glowing purple orb of Twilight’s magic, most ponies gave her only a passing glance.

A certain brown earth pony stallion gave her more than just a passing glance, but she was well out of hearing range by the time he yelled for her to come back.

After running pell-mell for several minutes in a mild state of panic (what else was new), River skidded to a stop at an intersection, looking frantically in all directions. “Where is it?!” she moaned. “The show does not give a good enough idea of the layout of this place!” The problem with running in a panic, she noted sourly, was that it did awful things to a person’s sense of direction. Now she couldn’t for the life of her remember which way she'd come from or, by extension, how to find the field in which she'd woken up a few hours ago.

Her pause also had the unfortunate side effect of giving space for the depression to land. River groaned again and sat on her rump, rubbing her temples with her hooves. “Probably won’t even be there if I do find it,” she muttered. “Chewie could be anywhere.” It was the Chip incident all over again, except this time it wasn’t even her fault, which made the whole thing worse somehow. River spent several minutes like this, wallowing in self-pity on a public street and in general not accomplishing anything useful, which is usually what happens when one wallows in self-pity for any length of time.

“Excuse me? Miss? Do you need help?”

River jolted and spun, locking eyes on the person who had unintentionally scared her half out of her wits. Three young ponies stood in front of her, wearing matching looks of concern: a pale white unicorn with pink-and-purple hair, an orange pegasus with a mane of magenta pink, and a yellow earth pony with a bow on her bright red tail. The three bore matching cutie marks in the shape of a shield.

A grin sprang onto River’s face, her depression momentarily obfuscated by delight. “Oh, it’s you guys! Hi!”

The looks of concern turned to looks of confusion as the Cutie Mark Crusaders exchanged glances. “Do we know you?” Sweetie Belle asked cautiously, adding the question to her original three.

River wanted to slap herself. Rule Number One! “Um, no, but I kind of know you, sort of,” she stammered, thinking quickly. “I’ve, uh, met your sisters. Recently. This morning. With Twilight.”

Apple Bloom’s face broke into a proud grin. “Oh, I gotcha! You must be in town helpin’ Princess Twalight with a friendship mission!” The filly stuck out her hoof, which River reflexively shook. “Well, you already know us, but Granny says it’s polite to introduce yerself at first meetin’s. Ah’m Apple Bloom, this is Sweetie Belle, and that’s Schootaloo, and we’re the Cutie Mark Crusaders!” All three puffed up proudly at their club name, which made River grin. Kids were cute in any dimension.

A few seconds of awkward silence passed before Scootaloo prompted, “And you are…?”

River blushed. “Oh, right! I’m…” Another pause as she glanced back at the B-shaped cutie mark on her flank, and then mentally sighed. Oh, why fight it. “You can call me River Babble,” she finished, adding Rule Number Four to her list. “Or just River is fine. Nice to meet you.” Clearing her throat, she quickly tried to change the subject. “Maybe you can help me! I’m looking for a field I was in a few hours ago. It, uh.” She thought hard for a moment. “It has a tree in one of the corners, next to a pond or something. I was in kind of a hurry, but I need to find it!”

“That’s…not a lot to go on,” Scootaloo said cautiously.

River (who will now be referred to mainly as River) heaved a sigh. “I know, my memory is crap. It was…over in that direction, I think?” she offered, indicating the street with her hoof.

Apple Bloom perked right up. “Oh, Ah bet Ah know where it is! There’s a li’l field like that on the corner of our farm!”

“It’s worth checking out!” Sweetie Belle decided. “You just follow us Crusaders, ma’am!” And the three fillies bolted off down the street at top speed. River soon raced after them, equal parts grateful for their helpfulness and sense of urgency, and irritated that even as a horse, she was out of shape.

They sped down a road that led away from Ponyville. Apple trees could already be seen in the near distance, and River felt a little wellspring of hope reopen inside her chest. She huffed words around deep breaths as she tried to keep pace with the energetic kids. “Thanks, I think I lost something back there!”

“No problem!” Scootaloo called, grinning over her shoulder. “The Cutie Mark Crusaders are always ready to help a pony in need!”

“Is that what we do now?” Sweetie Belle asked, starting to sound a little winded herself. “I thought we were mostly focusing on cutie marks?”

“Hey, helping people is helping people.” Scootaloo shrugged between strides. “And maybe we’ll help her find out something she didn’t know about her cutie mark!” River privately doubted this, since she’d designed her cutie mark specifically for the talents she already knew she had, but she was touched by the thought.

Within minutes, they arrived at a field, the buildings and orchards of Sweet Apple Acres visible in the distance. River looked bleakly out over the grass, wondering where to even start. Chewie was going to be nearly impossible to find, but she had to at least try…

…Hang on. Discord said he brought some of my other stuff through, too, right? If she looked for her wallet and things at the same time, maybe she’d get some results, especially since most of those items were distinctly more stationary than Chewie. The thought brought a little surge of hope. So long as she had a doable reason to keep searching, there was at least a chance she’d find Chewie in the process!

“So what’re ya lookin’ for?” Apple Bloom sat down beside the currently deep-in-thought unicorn, her red-maned head turning to look over the entire field.

“A couple of things,” River said distractedly as she began picking her way through the grass. “I’m not sure what all yet. Would you girls mind helping me look around, maybe just keep your eye out for anything unusual?” The idea of having extra help was even more encouraging, and it wasn’t like the fillies could damage much, although the idea of what a hoof meeting her phone would do to the screen made her wince.

“We can totally do that!” Scootaloo said, her eyes sparking with the challenge. “Come on, girls, Cutie Mark Crusaders Treasure Hunters!” There was a group cheer, and then the three fillies raced out into the grass, giggling and yelling half-baked ideas about forming search patterns. River grinned to herself as she went back to her search. Apparently the Cutie Mark Crusaders hadn’t stopped looking for new skills to try just because they’d finally gotten their cutie marks.

The search continued on in this way for a good twenty minutes, which was about when her helpers’ interests began to flag. River, feeling discouragement creeping in again, sat down for a moment to gather her thoughts. So far, there’d been no sign of anything unusual or even mildly interesting: no Chewie, no phone, no wallet, no whatever else Discord claimed he’d stolen when he kidnapped/dimension-hopped her. But then again, did she know that Discord had really taken her things? Lying to get what he wanted seemed on par with his actions up to this point.

Another, more guilty thought entered her mind, and she turned a worried glance towards the pointy castle poking up over Ponyville. She’d run off without letting Twilight know where she was going… “Just like he wanted,” River grumbled. Discord was probably thrilled right now, tricking her into abandoning the one pony who could help her get home while she went on this wild goose chase. Well, see how he liked it when she just trotted right back there! River stood up, back straight (horizontally, anyway), and scanned the field, opening her mouth to call the girls back in.

Something made her pause. River frowned, looking over the field with more focus now that she wasn’t distracted with the search. It looked…wrong. There was a tree over there, but… She racked her brain, mentally cursing her terrible memory. Hadn’t it been on the other side of the pond?

“Oh my word.” River groaned, putting a hoof to her head as the obvious clues that had been in front of her the whole freaking time came together. “We’re in the wrong field.” They’d wasted all this time looking, and they weren’t even in the right place—!

“Hey, Ah found somethin’!”

River turned to see Apple Bloom on the opposite side of the field, holding something small up in her hoof and waving it. It was impossible to tell what the thing could be from this distance, although considering her recent discovery, River felt confident that it couldn’t be anything of hers. Still, she trotted over to join the converging Cutie Mark Crusaders, who were already ooing and ahing over Apple Bloom’s find.

“What is it?”

“Ah dunno, Ah’ve never seen anythin’ like it.”

“The glass part kinda reminds me of the lenses on those fancy cameras ponies bring to my sister’s fashion shows, but it’s too flat.”

“What does – whoa! This little round mark lights it up! It must be magic!”

“What’re all those numbers for?”

“See what happens if you poke them—”

Understanding crashed in, and River bolted the last few yards with a burst of adrenaline. “WAIT! Be careful with that!” She skidded in the grass, nearly falling on her face in front of Apple Bloom. “Let me see, let me see it!” River gasped.

Apple Bloom held the thing out to her. It looked too small in the filly’s hoof, being meant for the delicate fingers of humans. A smile bloomed on River’s face as she looked down at a familiar rectangle of metal and glass, wrapped protectively in a black rubber casing. “It’s my phone!” She heaved a sigh of relief and reached for it. “I can’t believe it! Where did you find it?”

“Your what now?” Scootaloo asked, eyeing the portable game console with confusion. “What’s it for? Is it some kinda magic doohickey?” She ignored Sweetie Belle’s exaggerated eye roll.

“It was just sittin’ here in the grass,” Apple Bloom explained. The filly looked puzzled when River’s attempt to grab the phone knocked it to the grass; River blushed and bent down to grab it in her mouth, hoping desperately that her spit wasn’t somehow going to get into the electronics and fry it.

“Thish ish grea’!” Man, it was hard to talk like that. She reversed her decision and set it down in the grass again. A few very careful prods with the tip of her hoof entered the lock code, opening up her list of apps, and River let out a huge sigh of relief. “Awesome, still working. It’s a phone, it lets two people talk to each other from far away. It’s not really magic, per se, it’s…uh…you know what, that’s really hard to explain, let’s save it for later. I’m just glad it’s not broken…” She trailed off, several facts settling into her brain. River stared over at that pond with the tree on the wrong side again. “But...how the heck did it end up here?”

This question naturally caused a great deal of confusion, and River had to explain how she had realized that they weren’t even in the right field. That led to the girls pressing her for details about how exactly she “lost” her stuff, and River, being a painfully honest person anyway, had to struggle for an explanation that wouldn’t completely shatter Rules One and Two. She’d already learned the consequences of the first one with Twilight, and she wasn’t eager to break a few kids’ brains.

“Okay, look…” Her eyes cut to the side as the girls all looked up with expectant faces. River let out a slow breath. “Let’s just say that I, uh…met Discord…and, for reasons that will not be disclosed, he thought it would be funny to transport me here, along with some things that are important to me.” She cast a disparaging eye at the field. “And apparently he thought scattering those things all over creation would add to the joke.”

Apple Bloom nodded sagely. “That ol’ Discord gets up to all kinds o’ trouble, my sis says.” She thought for a minute, pawing the grass. “Maybe if we ask nicely, he’ll stop messing with you. He is an honorary Cutie Mark Crusader!”

“It doesn’t sound like that’s going to work this time, from what he says in this note.” Everypony turned to see Sweetie Belle holding a crisp piece of parchment paper. She blushed when she saw their expressions. “Don’t look at me like that! I just found it a second ago!”

The group gathered around Sweetie Belle and the note, River Babble taking it in her hoof. She noted with bemusement that she’d fully gained the knack for holding stuff in her hooves, which still made no sense even when she was looking straight at it. More important things to worry about, focus! River scanned the page, reading the words out loud with a steady decrease in enthusiasm.

“River, my dear, you’re just such a bore,

Turning adventure into a chore.

If you spend all your time only trying to leave

You’ll miss out on all of the fun to achieve!

So let’s play a game. You’ve had a head-start.

Prove to me that you’re not just an old fart.

I’ll give your things back. Just follow the clues.

And once you’re all done, you can leave if you choose.

You think that you know about ponies so well?

You’ll get your first clue when you cast your first spell.

P.S. I’ll throw Chewie in too if you’re a good sport and don’t tell on me.”

“Really? REALLY? Are you that bored? Did you steal this from a Dr. Seuss book?” River blurted. No answer came, although by now she was almost 100% positive that the conniving jerkface was watching her every move.

While the three girls took over the paper, trying to figure out the clue, River stared into the distance for a long time, trying to think. It sounded like, with this deal, Discord would be willing to give all her stuff back and find Chewie. There wasn’t anything in there about going home, but he’d sort of implied he’d do that, too, right? He was a jerk and she didn’t trust him as far as she could throw him, but…

And then there was Twilight. River swallowed a lump of guilt, remembering Applejack’s accusing questions and Twilight’s decision to trust her. I bet I look REAL trustworthy now, running off like that, she thought uncomfortably. In fact, she had just been about to go back. Was that why this popped up right when it did? Was Discord that worried about getting into trouble with Twilight? If he was really so concerned…it might mean he would keep his end of the bargain honestly. Twilight could probably be able to get her home, but leaving her stuff behind – especially Chewie – would be freaking awful. And she didn’t really need to check back with Twilight…right?

She didn’t like it. She didn’t like it at all. But finally, River heaved a purposefully loud and exasperated sigh. “Alright, I will do your stupid scavenger hunt, you dingus,” she yelled at the sky. “But you had better keep your end of the deal, including Chewie, or I’m marching straight back to Twilight and telling her everything, and you can keep my stupid wallet!”

“What’s a dingus?” Sweetie Belle whispered. Her friends shrugged.

Uncertainty tugged at her, but River shoved it back down. She could explain everything to Twilight later…somehow. And, well, maybe Discord had another point: she was kind of missing out on the coolness factor of travelling to other worlds by focusing so much on freaking out and going home, right? I mean, it’ll probably take a few days one way or the other, she reasoned. No more bothering Twilight, no more worrying about Chewie or going home; just a little adventure, and then everything would go back to normal!

“So where’re we headin’ first?” a voice piped up.

River turned a blank stare on Apple Bloom and her friends, who were looking up at her expectantly. “Huh? What do you… Do you mean you want to come along?”

“Well duh!” Scootaloo scoffed, her tiny wings buzzing with excitement. “Discord’s scavenger hunts are the best!”

“We’ll have your things tracked down in no time!” Sweetie Belle promised. “The Cutie Mark Crusaders are on the case!” She bounced with glee. “Go ahead, do the first thing! We already figured it out!”

“We think,” Apple Bloom corrected her. “The ‘first’ part doesn’t totally make sense…”

“The first clue? Wait, let me read it again.” River looked at the poem again, scanning the lines until she came to the bottom. “’You’ll get your first clue when you cast your first spell.’ What does that mean?”

Three very blank stares looked up at her. River felt her eyes sliding to the side in the uncomfortable silence. “What?”

“Um…” Sweetie Belle rubbed one leg against the other, looking embarrassed. “Miss River, you, um…you do know you’re a unicorn, right?”

River’s eyes crossed as she looked up, just able to see the tip of her horn. “I’m…I’m a unicorn. Oh, right!” Sensing the deepening confusion of her young helpers, River let out an uneasy laugh. “Riiight, yeah, of course! Um…so, I guess I just have to…cast a spell?”

Several agreeing nods. A knot tightened River’s stomach. “Um…any, uh…suggestions?” she stalled, hoping the extra few seconds would reveal some hint about what she was even supposed to do. Part of her felt a little giddy; she could do magic! Real, safe, family-friendly unicorn magic like Twilight did. This would be really cool if she weren’t completely positive she was about to blow her cover. The show made it sound like it took years for young unicorns to learn how to use their magic, and she was supposed to just cast one out of the blue? Thanks a million, Discord.

Scootaloo and Apple Bloom looked at Sweetie Belle, the resident unicorn of their club. Sweetie Belle kept eyeing River Babble strangely, but she seemed eager to help. “It doesn’t say what kind, so maybe…maybe a locator spell! I just learned one from Twilight last week!”

An idea came to River, and she brightened. “Great! I, uh, don’t know any of those. Do you…do you think you could teach me?” she asked nervously.

Sweetie Belle’s jaw went slack. “You don’t…you want me to teach you a spell?” Slowly, her cheeks bunched in an unbelievably huge smile. “A grown-up unicorn wants to learn a spell from me! This is so cool!” She bounced a few times, but then she settled, arranging herself into a very serious pose (which looked stinking adorable). The pale unicorn tilted her horn down, mouth set in a firm line. “Okay, so here’s what you do,” Sweetie Belle commanded, doing her best Teacher Twilight Sparkle impression. “First, you draw a small amount of magic into your horn, about the same as a really small Levitation spell. Then you think really hard about the thing you want to find. Let me know when you’re ready!”

Gulping, River adopted a stance similar to Sweetie Belle’s, and tried to focus inside herself, looking for any alien sensation that might be magic. She sent up a prayer, hoping for an epiphany. Lord, please help me figure this out, I’m going to look like a complete idiot and have to explain everything and it will totally freak them out— She took another deep breath. Focus. Focus. Wait, what’s…?

She felt something. River reached for it with her mind, and suddenly, she was very aware of her horn and the signals it sent through her brain. She focused on that, shutting off her other senses, and the signals became more and more clear. The magic was everywhere: inside her, around her, in the girls, in the plants, flowing on streams of current like wind, hugging the grass like layers of snow. A thrill shot through her, and before she knew it, the brand-new unicorn had sucked a huge amount of that magic up into her horn.

Everything went very, very bright for a second, and then River was wobbling on her legs, feeling like she’d just been blasted in the face by a sonic boom. A distant ringing sound slowly formed into the sounds of three excited voices growing louder.

“Red Delicious! Are you alright, Miss River?”

“That was awesome!”

“That wasn’t supposed to happen, I promise! Do you feel okay? Miss Babble?”

Slowly, River took a step, reestablishing her center of balance as the world came back into focus. The dazed feeling was fading, although she still had a doozy of a headache. “Wow…what…what did I do?” Her voice sounded a little slurry in her own ears. Maybe magic worked better in small doses.

Sweetie Belle stood by her leg, her green eyes wide with anxiety. “I’m not sure, but it looked like you cast an Illuminate spell and it went all wrong! I totally didn’t mean for that to happen, I’m so sorry, I’m the worst teacher ever!”

Shaking her head, River looked around to make sure that she hadn’t caused any serious damage with whatever that was. But everything looked normal. Okay, Rule Number 5: be extra-super-stinking-duper careful with your new superpowers. A giddy giggle almost escaped her at that thought, but she clamped it down, and gave Sweetie Belle a reassuring pat. “No, Sweetie Belle, that wasn’t at all your fault. It was me. See, I’m…uh…I’m kind of not as good at magic as most unicorns yet,” she said carefully, wincing at the near-fib. She’d really have to watch her words if she didn’t want to accidentally stray off of Rule Number 2. Or tip off the kids to the fact that she was more than a little abnormal for a unicorn.

Now it was Sweetie Belle giving River a reassuring pat, much to River’s surprise. “It’s okay, Miss River. My parents always say, some unicorns are better at magic than others, but that doesn’t make them less important!”

“Heck, I’m a pegasus and I can’t really fly yet,” Scootaloo added, buzzing her undersized wings for effect. “It’s cool.”

That was about the sweetest thing she had ever heard, and River was seriously debating if it was okay to randomly hug these kids when Apple Bloom let out a shout.

“Look! I guess ya didn’t need to do any particular spell, after all!”

True enough, when River looked down at the parchment in her hoof, it bore a soft, white glow. The glow shot down to the ground and then away, forming a long, dotted line that soon extended out of sight towards the Apple Farm. The Cutie Mark Crusaders let out a cheer, and River almost joined them. But she definitely wore a smile as the foursome followed the line towards their next clue.

Guilty conscience aside, maybe she was going to have some fun!

----

Rarity, Applejack, Pinkie Pie, and Rainbow Dash moved at a quick trot (or flight, in Rainbow’s case) down the street, following the purple sphere. Rainbow Dash was rubbing her forehooves together and wearing a devilish grin. “I bet we find her opening some doorway to another dimension and letting in weird monsters to take over Ponyville!”

Rarity raised an eyebrow at her flying friend, her delicate white hooves working a little harder to keep up with Applejack’s more athletic pace. “And why, may I ask, does that excite you so much?”

Rainbow Dash shrugged, turning a loop-de-loop. “We can take anything she can dish out! You saw her, she’s a total pansy. Plus I’ve been itching for a good fight against evil. It’s been too quiet around here since the whole Starlight Glimmer thing.”

Applejack shuddered, never taking her eyes off of the purple ball of magic. “Don’t remind me o’ that. Durn craziest thing we ever been through. Me, I wouldn’t mind a little peace an’ quiet for the rest o’ the year!”

The blue pegasus was about to reply when a brown stallion shot towards them from farther up the road, passing the purple ball of magic without a glance. He had some sort of hoof-held device clamped between his teeth, which became obvious when he tried to talk around it. “Ladish! Migh’ Ah ha’ a wor’ w-oo?”

“Ya might if’n ya take that thing outta yer mouth, Doc,” Applejack chuckled, slowing to a stop along with the others. The girls were all familiar with the local (possibly mad) scientist, and a small chorus of hellos greeted him as he trotted over. Doc quickly removed the device from his mouth, holding it in his right hoof now that he didn’t need said hoof to run.

“Ladies,” Doc panted, wiping sweat from his brow. “A pleasure as always, but I fear I have grave news. By any chance has Princess Twilight Sparkle been experimenting with the impregnable barriers between dimensions today?”

Glances were exchanged among the mares. Except for Pinkie Pie. “Yepperdoodle!” the pink mare replied cheerfully. “Although really it was River who came through first and now Twilight’s trying to—”

“What she means is,” Applejack interrupted, “yeah, Twilight’s been fiddling with somethin’ to do with other worlds back at the castle. How did ya know about that, Doc?”

Doc Turner held up his device again. “Several pieces of equipment in my laboratory are dedicated to measuring various magical, meteorological, and metaphysical phenomena in the vicinity of Ponyville and the surrounding areas. I suspected that Princess Twilight was engaging in studies of an inter-dimensional nature for months now. If she has truly found a way to pierce the veil between worlds at will, she has my profound envy, as I’ve yet to garner my own method of affecting such a portal,” he added distractedly, before giving his head a vigorous shake to come back to the point. The brown earth pony glared accusingly at the device in his hoof, as if the information he was getting were its fault somehow. “But the readings I’ve received since this morning are of a most concerning nature! I must speak with the princess immediately to determine if my worries are well-founded or not, because if they are, we may have a very serious problem on our hooves.”

More glances were exchanged. Rarity worried her lip for a moment. “I apologize, Doctor Turner, but I’m afraid we’re all a bit in the dark about the true nature of these portals to other worlds. Might I trouble you to explain exactly what kind of problem we could be facing?”

“A breach.” The term made no sense to the girls, but the grave look on the doctor’s face made it clear that the meaning was not good. “If my hypothesis is correct, something alien has entered our reality, which is not, of course, very dangerous in itself,” he added with a small chuckle, as if this were all perfectly obvious. “But my equipment is telling me that an especially peculiar anomaly is straining the very barrier that separates our reality from others. I’m afraid that if we don’t isolate the cause quickly,” and once again the doctor’s face turned quite serious, “that barrier could be breached, and there is no way to tell what sort of reality it may open us to.”

Rarity, Applejack, and Rainbow Dash were all staring at each other in open, mutual worry now. “I think we better pick up the pace on findin’ River,” Applejack said firmly. Doc was about to ask for clarification when the three girls turned back the way they had been going…and Applejack snapped, “Horse apples! Dangit, Twalight!”

The magical sphere they had been following, which apparently did not work on the same stay-close principle as its smaller counterpart, had continued on its way while they were standing around talking. It was nowhere to be seen. A chorus of groans filled the air.

“This ‘River’ that you speak of…” Doc Turner said slowly. “Would she happen to be a black unicorn, blue-striped mane, runs about with a rather frantic look in her eye?”

The girls spun to him. “Yeah! How’d you know? Did you see where she went?” Rainbow asked, finally coming to a landing in front of the Doc. “She came yelling at Twilight this morning with a funky story about being a human from some other world, but she took off while Twilight was trying to send her home. We’re tracking her down and taking care of any crazy alien monsters she brings to Equestria,” the mare added with pride.

“There ain’t gonna be any monsters, Rainbow,” Applejack said flatly.

Doc dipped his head in a confident nod. “I knew that young lady had something to do with the spike in my equipment! She passed this way not long ago, in quite a rush. I believe that last I saw her, she was heading towards the Apple Farm in the company of our resident Cutie Mark Crusaders.”

“She’s with Apple Bloom?!”

“She’s with Sweetie Belle?!”

“Oh hey, she’s with Scootaloo?”

Rarity and Applejack glared at their significantly less concerned friend while Doc tilted his ears back. The earth pony gently cleared his throat. “Ah, yes. Is that not to your liking?”

“Ah dunno, Doc, you sure didn’t make her sound safe t’be around,” Applejack pointed out. She turned, narrowing her eyes as she looked towards the Apple Farm in the distance. “If she gets mah li’l sister hurt…”

“Then perhaps I can be of assistance.” Doc gestured their attention to the chunky, softly-beeping device in his hoof. “This contrivance of mine is calibrated to point towards the primary source of the anomalous readings. No doubt it will take us straight to your missing interdimensional traveler.”

Applejack tilted her cowboy hat back, one eyebrow raised in surprise. “You got one o’ those, too? You n’ Twalight sure like yer fancy gadgets.”

“Oh? Perhaps I will have the opportunity to survey her equipment one day,” Doc said cheerily. “I didn’t realize she was such a practitioner of the practical scientific arts.”

“But I thought that it was most urgent for you to speak with Twilight about the, ah, situation you described,” Rarity reminded him, somewhat reluctantly.

“Perhaps,” Doc said with a nod, “but it would appear that the anomaly is centered around your visitor, so she would be the logical place to start in isolating the cause of this strain on the dimensional curtain. Ergo, it would make the most sense to assist in finding her first and foremost.” When none of the girls could find any fault in his logic, Doc focused back on his device, turning in a slow circle. It wasn’t long before a small arrow appeared, and the doctor’s green eyes lit up. “Tallyho! The game is afoot!” He reared up and took off down the road with the four mares following close behind.

Their journey soon took them out of town, Rainbow Dash zooming ahead once in a while to scout. Applejack and Rarity did their best to hide their concern for their sisters; after all, River hadn’t seemed dangerous. But the doc’s warnings about “breaches” and “problems of most concerning natures” weighed rather heavily on the mind. “I hope Sweetie Belle isn’t getting into trouble,” Rarity murmured, flipping away a lock of purple mane jounced out of place by their running. “At least no more than usual.”

“I was gonna say.” Applejack forced a chuckle. “Them three get up to more shenanigans than every other colt ‘n filly in town.”

“Yeah,” Rainbow Dash said suddenly from over their heads. “‘Cause they know what it takes to be awesome. I mean, y’know, as awesome as kids outta be,” she added with a flip of her hoof.

Rarity shot Rainbow Dash a coy smile. “Was that a hint of concern I heard just now, Rainbow?”

Rainbow folded her hooves in a huff, slowing her wings to a steady hover over her friends. “Hey, I totally care about Scootaloo! I just trust her to stay cool and be ready for anything. Just like I taught her,” she added proudly.

“Awwww!” Pinkie gushed. “Big sister Rainbow Dash~!” She giggled as Rainbow buzzed her head so close that her main puffed into an extra thick tangle of curls.

“So you ain’t the least bit worried about her an’ the girls hangin’ around this funny unicorn?” Applejack asked skeptically. “Considering you also seem pretty durn sure she’s gonna let in an army o’ monsters t’take over Equestria.”

Rainbow opened her mouth to reply, then paused, worry flickering across her face. But it was gone in an instant, covered by a casual shrug. “Aw, she’s… Come on, guys, I’m sure nothing really bad is gonna happen. Nothing those three can’t handle!” she boasted.

“All the same,” Applejack replied, brow furrowed, “I’ll feel a ton better once we see they’re alri—” The orange mare suddenly skidded to a halt, causing Rarity and Pinkie Pie to pile up behind. “Wait an apple-buckin’ minute, this ain’t the way to mah farm!”

Everypony looked up and quickly ground to a stop. Doc was so focused on the directional arrow on his device that he continued five more paces before Rarity cut off the levitation spell she’d been using to help him read it while trotting. “Eh, what? I believe we’re quite close, ladies, the signal is…” The words died as he looked up at what everypony else was staring at.

The edge of the Everfree Forest.

Doc stared at the wild and forbidding trees that abruptly sprouted from the ground twenty feet ahead of them. He looked at his device again, just to be certain, and…yes, it was most certainly pointing straight towards the ominous forest, beeping insistently. The doctor cleared his throat, running a hoof under his collar. “Well, ah… Perhaps your friend didn’t go to the Apple Farm, after all.”

“Doc,” Applejack said flatly. There was a world of danger in her quiet tone. “Are you tellin’ me that this mare we’re a-lookin’ for might’a taken our li’l sisters into the Everfree Forest?”

Doc scratched his ear with one hoof, shooting puzzled glances between the forest and his gadget. “I…am not altogether certain, Miss Applejack. In fact, I think…” He picked up the device again and continued forward. The girls could hear the beeping of his machine grow louder, and faster, and louder, and faster, until—

“Great whickering stallions! What have we here?”

Another mass movement of ponies soon had the four Elements of Harmony surrounding the doctor and his new discovery. The brown stallion gently lifted it in his hoof, green eyes wide with scientific intrigue. “Great whickering stallions…,” he whispered. “I’ve never seen anything like it!”

It was a rectangular box or block of some kind, a little larger than Doc’s hoof; Rarity guessed it to be made of a mildly transparent plastic. “And quite a lovely shade of blue, if I do say so,” she added. A seam along the side made it look like it could come apart, or be opened. And on what they decided must be the top, there was stamped a strange symbol or crest: a sword with two thin dragons facing each other from either side.

“Wow! River sure shrank since we last saw her!” Pinkie Pie said thoughtfully.

“Darling, I really don’t think that’s—” Rarity paused when she saw Pinkie’s playful wink. “Right, very funny, Pinkie Pie,” the white mare finished dryly. “I think we can all agree that this wasn’t what we were expecting to find. What do you make of it, Doctor?”

Doc very gently tilted the object up, down, back, and forth, murmuring under his breath. He waved his equally peculiar-looking hoofheld device over the blue rectangle again, and was rewarded with another round of excited beeping. “First of all, I must apologize, ladies,” Doc said, although his giddy tone kind of ruined the apology. “I had naturally assumed that your displaced companion would have the strongest reading, and therefore lead my equipment straight to her. But this…thing has caught its attention somehow.” He tapped his chin in thought, then ruffled a hoof through his spiky mane in more thought. “If the readings are reacting to something brought with the mysterious mare rather than the mare herself, perhaps that’s—”

“So whadda we do next for findin’ River an’ the girls, Doc?”

Doc snapped his head around, and realized that the four mares were staring at him expectantly. “Eh? Oh, right, of course, missing not-a-pony, young fillies in peril, right, yes, top priority.” He cast a longing look at the blue thing at his one hoof, and the beeping device at the other. “Ah, but…this may be rather important, if my readings are any—”

“No sweat, cadet!” Pinkie Pie bounced forward and scooped up the blue thing, depositing it directly into her bouncy mane. Doc was still trying to process this mode of storage when Pinkie turned and trotted back in the direction of Ponyville. “You guys have super-duper fun finding River and your cutie-patootie little sisters, and I’ll take this back to Twilight for her whosamawhatsit and give her the updates on our special secret mission! Toodles!”

Doc shook his head hard, and reached a hoof out towards her, calling, “You must tell her to be careful! The breach could be…tampering might…” He dropped his hoof in resignation as Pinkie Pie bounced out of sight over a small hillock. “I don’t feel completely comfortable with what just happened,” he sighed.

“Eh.” Rainbow shrugged. “It’s Pinkie Pie. Either she’ll make everything go crazy wrong, or find some kooky way to save the day. Either way, it’ll probably work out.” Ignoring the earth pony’s attempt to debate the appeal of such odds, the blue pegasus shot into the sky and took a long look in all directions. “Show us which way to go next, already, Doc!” she hollered. “I don’t want Scootaloo beating up all the monsters before I get a chance!”

Applejack and Rarity were already staring at the Doc when he looked at them, and so they caught him with the full force of their combined Maximum Level Distress Stares. (Rarity had always been far better at this than any pony in town, but when it came to her sister’s safety, Applejack could turn up the voltage pretty high herself.) The dual effect cut right through any lingering arguments Doc might have had for separating himself from the search to continue his research on the potential world breach problem. He held up a hoof in defeat, chuckling. “Right, yes, of course. We must locate your friend if we’re to have any real understanding of what’s happening! If you’ll just give me a moment.”

A few agonizing minutes of fiddling passed, involving methods and means that completely mystified the three non-sciencey mares. But they needed his help to track down River and the girls, so Rarity and Applejack made sure to smile and nod when he held his strange little device up again, the tone of its beeping a little different than before. “There! Now it should only take us to organic sources,” he said proudly. “And— Ah!” The beeping was already growing in volume, the arrow pointing them into the distance.

Doc had always had an excitable nature, and now, once again, the thrill of the chase and the lure of scientific mystery filled him up with excitement. “Come, my friends!” he crowed dramatically. “The game is afoot once again!”

“This is sure turnin’ out to be an interestin’ day,” Applejack muttered as she took off after the brown stallion.

“I only hope that it doesn’t get too much more interesting,” Rarity sighed, once again lamenting not keeping to her exercise regime this past month.

As the four ponies disappeared over the hill, a glowing, white, dotted line materialized, mark by mark, across the grass coming from the opposite direction, until it formed a small, glowing circle where River’s 3DS had just been. Nopony was around to notice, but then, most ponies wouldn’t have been too concerned even if they had.

They might have been a little concerned if they’d seen the tiny hole in space that ripped open above the glowing circle. Or the yellow eyes that peered through before it snapped shut with an echoing POP!