Rainbow Dash struggled fiercely trying to bat the creature away, but where her movements were sluggish and clumsy under the water the creature’s were lithe and nimble. What’s more, it had help.

Even as one of them pulled her down by her tail, another shoved her down into the depths. More soon joined in, pulling on her limbs and forcing her downwards. It was hard to see through the muddy water, but from what Rainbow could tell the others were in the same situation.

Frustrated, Rainbow tried to either let out a scream or bite at one of her attackers, only to be rewarded for her trouble with a long semi-prehensile tail being wrapped around her muzzle.

Her lungs burned for air and she reflexively tried to open her mouth, desperate to fill her lungs, only to find that the tail around her muzzle had constricted further. Rainbow looked up at the surface, obscured by the muddy water. It might as well have been a mile away. Fear began to creep into her mind; not only was she about to die, but it would be in the murky depths—swallowed up and forgotten, as if she had never existed at all. She was almost grateful for the water, because she had no way of knowing whether the liquid on her cheeks was river water or her own tears.

Dying, terrifying as it was, wasn't even the scariest part. It was that when it counted the most, she had failed. Celestia was gone, Nightmare Moon would triumph, Rainbow's friends would remain her puppets ... and she had led five good ponies and one zebra to nothing but a watery grave.

Her hooves hit the riverbed. Rainbow’s vision swam from lack of air. She looked up to see a whole swarm, or school she supposed, of the creatures circling around her and her friends. They were swimming faster and faster. She blacked out for a minute.

When she came to, she was laying on the cold, muddy ground. She reflexively opened her mouth to take a deep breath. It wasn’t until a few seconds later that her brain had booted up enough to realize that she should’ve been choking on water, but wasn’t.

“What the hay?!” Dash exclaimed as she got up and took a breath. She wrinkled her nose. It smelled fishy and moldy and cold, but it was still air. She shivered, shaking the water out of her coat. Looking around, she saw a giant bubble shimmering around her. Outside she saw the creatures curiously swimming around it. Experimentally, she gently pushed her hoof at the edge. It wobbled but held firm.

A groan drew her attention to her friends as they stirred themselves. Rainbow darted over. “Everypo—everyone okay?”

The mystic zebra spat out a mouthful of water. “My sincerest thanks for your concern, though no injuries can I discern.” Her mohawk drooped slightly but somehow managed to more-or-less maintain its shape.

Rarity shuddered, cold and wet and appalled at her state. “My hair!” she moaned, tugging Applejack’s borrowed hat over her face. “Don’t look at me!”

“Oh for the love of…” Applejack shook herself dry, showering the others with droplets of water. “She’s fine.”

Rainbow might’ve guessed the two of them would be alright, so long as they had the other to distract them from whatever was going on around them. Pinkie Pie was resilient enough in her own strange way, poking away at the bubble. Rainbow spotted Twilight looking concerned at this development, but at least it was preventing her from thinking too much about her most recent ordeal.

Dash looked over to Fluttershy just in time to see her daintily sneeze. Her long mane was drenched and weighing her down so she looked even smaller than usual. “It’s so cold down here.” Fluttershy looked out at the river, held back just beyond their bubble of air. “I could spend time with so many animals if I could stay here!”

“Some other time.” Rainbow Dash shrugged her wings, shaking the water out of her feathers. “Preferably never. Okay, enough sightseeing. We need to figure out a way out of here!”

“It would be easier if we knew exactly what happened,” Twilight offered.

Rainbow wasn’t having it. “We all know what happened: we’re at the bottom of the river. It’s pretty obvious. Now we’re trying to figure out how to make it un-happen.” Twilight scrunched up her nose, either at the dismissal or the poor grammar.

“Easier said than done, sugarcube.” Applejack looked up, trying to see the surface. “I don’t think we’re gonna just swim past all them fish-ponies.”

Fluttershy raised her hoof. “Um, excuse me…”

Rainbow looked to Twilight, barely even noticing Fluttershy. “Twilight, how about you poofing us to the surface?”

“‘Poofing’?” she repeated incredulously. Every time Rainbow tried to describe complex magic, a spellcaster died of embarrassment. “That’s what you’re calling it now?”

“Um … I’m sorry but…” Fluttershy tried again.

“Can you do it or not?” Rainbow Dash demanded.

“I don’t know, I’ve never tried teleporting this many ponies through that much water. I don’t know how that could affect the—

“Wait!” Fluttershy snapped. While it was slightly louder than her normal voice, it still managed to draw the attention of everypony and zebra present. “Oh! Sorry! But um, the—um, they’re watching us.” She said in a hushed tone. “I—I think they’re waiting for something.”

Rainbow snorted. “Oh they are, huh?” She marched up to the barrier and looked out at the ogling creatures. Not struggling for life and breath made it easier for her to take a good look at them.. What she was able to make out through the murky water wasn’t that much different from a normal pony. They had gills on the side of the sides of their necks that would close tight, then slit outwards before closing again in a steady rhythm. Their eyes were slightly bulging and as they opened their mouths, Rainbow saw rows of tiny, sharp teeth. Their tails expanded out into flippers while fins flapped steadily to keep them moving. What's more, she spotted what could only be a cutie mark on its side.

That's when she recognized what they were, her eyes widening in shock. "No way! These are seaponies?!" They were other ponies besides pegasi, unicorns and earth ponies. But they were either so rare or kept to themselves so much that they had largely passed out of living memory—unless, of course, your life happened to be thousands of years long. One of these long-lost ponykin were the seaponies and their merpony cousins. Being aquatic, terrestrial ponies seldom encountered them and were considered little more than myth and rumor, not unlike the Twinkle-Eyes.

Apparently they had more bite to them than that. “What do you want?” Dash demanded.

The pony head pushed forward until it breached the barrier between river and air. Rainbow jerked back, half expecting the river to pour in through the bubble. Instead, the seapony looked at her with blinking, bulgy eyes. “We … talk,” it gurgled and slurred in a somewhat feminine voice. “I … Wave—dan—cer.” It burbled. Then it quickly darted its head back into the river, only to re-emerge a second later.

“Did you do this?” Twilight stepped forward, indicating the air bubble with her horn. “Did you make it so we could breathe down here?”

“Yesss,” hissed Wavedancer. “Not want … shore ponies drown.” She gave them a fish-eyed glare. "Unless—necessary."

Rainbow extended her wings. “What’s that supposed to mean?” she demanded. “You drowned us so you could save us only so you could drown us later?!”

The seapony retreated back into the water and began to confer with one of its fellows. From behind the bubble they heard a rushing flow of burbling sounds. Wavedancer poked her head back into the bubble, hissing angrily. “You ... polluted the river." Her fins flapped in agitation as she darted back out and in again, the muddy water swirling around her. “Seaponies migrate each year. Shoreponies block rivers … dam streams … make it harder to reach spawning grounds—other seas—other sea ponies!” She retreated back into the water again. “Now ri-iver choked ... can barely see—hard to bre-eathe ... Somepony must pay!"

Well, horseapples.

Rainbow Dash barely suppressed the urge to wince. That would've been as good as an admission of guilt and she didn't think the seaponies were feeling merciful at the moment. She felt bad for what they had put them through, however unintentionally. But since they were on a bit of a schedule what with saving the entire world on all, getting bogged down here was not something she was big on. Applejack trotted up next to her, looking apologetic. Rainbow didn’t think a simple sorry was going to help matters, so she quickly shoved her hoof over Applejack’s muzzle before she could admit this was their doing. "Look, we don't know what happened with the river," she lied breezily, ignoring Applejack’s glower. “Things are just kinda chaotic. We found this tree lying on the bank and decided to use it for a boat. We don't know what caused the mudslide.”

“Ponies lie.” Wavedancer conveyed scorn through her burbles. She ducked back into the water and bark-squealed something at her fellows before returning. Rainbow spotted other seaponies converging around the air pocket. Wavedancer explained, “Seapony law ... says innocents not punissshed … but know at least one of … you downed trees. We ask you once ... tell us who did it. Guilty stay. Rest go freeee." Her gills flared as she looked from Rainbow to Applejack and back again. “Until we get … answer, nopony go. All stay.”

Rainbow reared up and took a swing at Wavedancer who ducked back into the water at the last moment. “No way!”

Wavedancer wriggled her way up and poked her head back in near the top of the bubble. “Seaponies control water … we can hold it back for a while. Not forever.”

Rainbow fumed even as she wracked her brain. What to do? She felt her wings twitch in impatience. Being trapped down below, with no sky overhead, wasn't helping her mood. She begrudged every second she was standing still instead of moving to stop Nightmare Moon. Rainbow wasted a moment wishing Celestia was here, sure that she could convince the seaponies to fly if she had to. She squashed the twinge of self-pity accompanying that thought and took a breath. She was a little calmer, but no closer to an answer. She had to be out there to defeat Nightmare Moon, but she wasn't about to leave any of her companions down here either. She looked briefly at Applejack, who was clearly unhappy with this whole situation.

As much as she hated it, part of Rainbow’s mind went back to some of the lessons Celestia had taught about leadership and ethics—in particular the ones where leaders had to leave behind or sacrifice somepony in order to carry out their goal if there wasn’t any other way. Rainbow Dash knew in her gut that Nightmare Moon wouldn’t be stopped without her. Taking the blame and saving her friends wouldn’t accomplish anything if Nightmare Moon stayed in power anyway. And they weren’t going to do anything at all if they all stayed down here. The logical thing to do would be to let Applejack stay behind and come back for her later. After they defeated Nightmare Moon, they could make some kind of arrangement or simply force the seaponies to surrender her.

However, Rainbow and logic had a complicated, messy relationship, the kind where they wanted to be together but also see other ponies. No matter how correct it sounded in her head, Rainbow couldn’t accept that throwing Applejack under the cart and leaving her behind was right. Because it wasn’t right. At all.

Rainbow gnashed her teeth. Applejack had taken her into her home and become her friend even though she barely knew a thing about her. She had Rainbow’s back since this whole mess started and she was not going to toss her away because it was convenient! Except … she frowned. Applejack had taken the reveal that she was the Queen’s student pretty hard. She’d been more guarded around her, less trusting since then. Maybe Applejack would rat her out instead? Rainbow did know how much she cared about her family and her farm. The idea of being away from it might be enough to convince Applejack to…

She shook her head, unable to really believe it, but unable to completely dismiss the possibility either.

What mattered more? That annoying, rational part of her mind whispered. One pony or all of Equestria? The answer seemed obvious. Obvious, and wrong.

Wavedancer poked her head back into the bubble and interrupted her dramatic inner monologue. "Time up! Who is guilty?!"

The moment of truth. She closed her eyes and rubbed her head. No matter how much she thought it over, no matter how much conflicting ideas crashed against each other—she couldn’t do it. Rainbow couldn’t abandon a friend or leave Equestria in the lurch. She was paralyzed. Rainbow felt her mouth start to move, but even she didn’t know what she was going to say. Nor would she ever learn, for Applejack spoke first. “It was me. I did it. I knocked over your trees and I’m powerful sorry. Let my friends go.”

“Applejack, shut up!” Rainbow hissed, shaken from her hesitation.

The seapony tilted her head in confusion before ducking back into the water to burble and cackle at the other seaponies. She reemerging a moment later in front of Applejack, floating at eye level with her. “You … knocked over the trees, flooded river with muck?”

“Yes ma’am.” Applejack nodded. "I didn't know there were ponies living in these parts. If I knew, I would never have done it."

Rainbow Dash grumbled, but since things were already about as bad as they could be, she decided to own up to her part in the whole mess. "She's not the only one who downed those trees. Heck, I knocked down way more than she did!"

Now it was Applejack's turn to glare at her. "First of all, last I checked you took down maybe one more than me. At best.” Rainbow opened her mouth to protest, but Applejack talked over her. “Secondly, it was my idea in the first place. You wouldn't have thought of it if we had stayed there all day. That makes me responsible, so simmer down or I'll make you button your lip."

“Why confess? Why not blame her?” Wavedancer warily asked, indicating Rainbow.

Applejack straightened herself and looked her right in the bulbous eye. “I was raised not to tell fibs or to let some other pony take the blame for my mistakes. If it means you’ll let my friends go, then do what you want with me. I did it and I'm responsible for it.”

Wavedancer looked from Applejack to Rainbow Dash and back again. After ducking back into the water again, she stared at the orange earth pony. “Unexpected.”

“I’ll say.” Rainbow looked at Applejack, stunned. “I—I don’t get it. You won’t be able to go back to your family.”

“I know.”

The pain in Applejack’s voice made Rainbow’s heart ache. “Then—then why say anything? Why not say it was me? For pony’s sake, I thought you were mad at me!”

“I am—or was, anyway.” Applejack shook her head. “I thought I was over it, then Rarity had to give up her necklace and I remembered how sore I was at you and—” She rubbed her eyes. “Look, I wasn’t even mad so much as I was scared for my family. I’d do anything for ‘em, to be there for them … but if I lied and let you take the blame for it, well, then I wouldn’t be me. So even if I was with them, it wouldn’t be me who was there. Or something, shuddup, I’m tired.” She shook her head again. “I know it don’t make much sense. But a pony who’d run out on her friends to save her own tail—that wouldn’t be the kind of pony my family deserved. I don’t even know what good I could do them if I was like that.”

Rainbow Dash didn’t know what to even say. Applejack wrestled with something for a minute, then took a deep breath and began again. “If I’m being honest with myself, maybe I wanted to be mad at you, but for all the wrong reasons.” Seeing Rainbow’s confused expression, she explained. “Before you showed up, I was the pony everypony turned to when they needed something dangerous done. If a little filly wandered off and got lost, I was the one who brought her back. If Timber Wolves came down from the Everfree, I was the one who herded ‘em back, in pieces if need be. Need a pet rescued that got lost out in a storm? That’s what I’m here for. Anytime there was a contest or competition, I was there: the face of Ponyville.” She let out a small sigh. “Then you come flying into town with your rainbows and your fancy aerial whatsis and within a week, all the foals in town have started up a Rainbow Dash Fan Club. Shewt, Apple Bloom's having it meet up in my old clubhouse on my own farm.” She clucked her tongue. “Can’t pretend that didn’t sting a bit.”

“Oh.” Rainbow lowered her ears. “Um, sorry?”

Applejack waved her off. “Don’t you be apologizing for my stinkin’ thinkin’, sugarcube. I had never wanted a fan club; more to the point, I never needed one. Still don’t. But I let it bother me more than I should’ve. I didn’t do all those things for the attention, but I can’t pretend I didn’t appreciate, well, being appreciated. Now here you are, the Queen’s student, here to save the day from Nightmare Moon. Bit of a bigger deal than some old Timber Wolf, amiright?”

Rainbow didn’t deny it. “Well, yeah, but that sounds like more of a reason for why you could’ve just kept your mouth shut or let me take the blame. You could’ve been the one out there, saving the day, being the hero for your sister...”

Applejack snorted. “Are you still not getting it? However much my pride might sting at seeing you be the one the whole town admires now, I ain’t so petty or small-minded that I’m gonna go around thinking of ways to bring you down just ‘cuz I’m feeling put-out. Shewt, I wouldn’t do that on any normal day of the week, and I sure as sugar ain’t gonna do it when the whole world is at stake. You’re the Queen’s student, you’re the one whose friends got snatched, you’re the one who found Zecora and found out about the Elements. If anypony’s got to see this through to the end, it’s you.” She rolled her neck. “Now don’t go letting that get go to that big ol’ head of yours, I still don’t think you can do it all on your lonesome, great destiny or no. But if there’s a choice between me or you, and it’s over something that was my fault to begin with … then I’ll suck it up and take the hit.” She stomped her hoof. “It’s the only way I can be honest to myself, and be the kind of pony I want Apple Bloom to be proud of.”

Rainbow Dash bit her lip.

Wavedancer was silent for a long time as well. “Tell us why you need cross river,” she said in as soft a tone as her burbling could convey.

Applejack flicked her tail. “What Rainbow Dash said about us not wanting to dam the river was true. We only wanted to cross the river to get to the old palace so we could stop an evil pony from making it night forever. You must’ve noticed that the sun should be up by now.”

Wavedancer hesitated. “This true.” Her flippers shook in agitation. “Tides all wrong. Moon not supposed to be like this.” She bit her lip. “This happen once before. Many thousand of tide changes ago. Caused seaponies to flee from shore, move deeper into oceans.”

“That was Nightmare Moon.” Applejack stepped forward. “She was keeping the moon in the sky then just like she’s doing now. We needed to cross your river to stop her. Now, I'm not looking to escape punishment for what I did, but if you let us go then I promise, I'll come back once we’re done. I’ll plant whole new trees along the river, and get my kin to help clear the muck out of it."

The seapony tilted her head, considering this. “What you swear by?” Wavedancer asked.

Applejack straightened up. "By my heart, hoof and bone, by family, hearth and home. By all the apple trees I’ve and my kin have planted for generations out of mind—we will make everything right, and I do mean everything.” She offered a wane smile. "Even let you lock me up permanently afterwards, if'n that's what you want.”

“AJ!” Rainbow Dash tugged on her tail with her teeth. “Shuddup!”

“Let go Rainbow!” She flicked her tail free and gently whacked her muzzle with it. “This is the way it has t’be.”

Rainbow Dash leaped and tackled Applejack to the muddy ground beneath them. “No chance! I’m not going to let you throw your life away!”

Applejack struggled, pulling Rainbow into the mud with her. The two grappled, Rainbow not sure if she was angry or relieved by Applejack’s actions—and the confliction only made her madder. They wrestled in the mud until they were interrupted by a font of water, spraying the two and forcing them apart. Rainbow coughed and spat, before looking up to see Wavedancer with a dribble of water leaking from her lip.

“Enough!” she barked. “Seaponies decided!” Rainbow felt her guts churn in tense anticipation. Wavedancer studied their expressions before elaborating. “Land pony promise to return?” Applejack nodded. Wavedancer gave a burbly sigh. “Seaponies not want hurt land cousins. Wanted ... peace after moonquake. But land ponies forget us. Maybe time to not be forgotten. So we let you … go. All go. Then after trees planted, you go home.” The seaponies in the river clapped their flippers and dove in circles, expressing their approval.

Pinkie cheered. “Hooray! Thank you! You’re the best seaponies ever!” She reached out and managed to hug Wavedancer through the bubble. The confused seapony struggled until she relented, patting Pinkie’s back with her flippers.

“Shoreponies much strange … but good,” she announced. “You stand together … like real school of seaponies. Come, each shorepony. Grab seapony. We take you to surface. Get ride down river.”

Rainbow Dash hesitated, not completely ready to accept the good word of a group that had been threatening them less than five minutes ago. But seeing the rest of her companions head over to the edge of the air bubble, she realized there really weren’t any other options. She was reminded of something she’d learned at flight camp: Whether you’re flying or falling, you don’t abandon your wingpony.

As they approached the edge, seven seaponies swam close to them. They turned, presenting their backs to the group, their intention plain. Rainbow slowly reached her hooves through the bubble and gently wrapped them around the slender neck of the seapony before her. She wrinkled her nose, trying to ignore the fishy smell and the unusual touch of wet scales. Once the rest had done the same, they were off.

Rainbow took a deep breath before being pulled through the air pocket and back into the chilly river. She felt her ride shoot up towards the surface as the air bubble collapsed behind them, the air bubbling upwards and helping push them to the surface.

They group breached the water, taking huge gasping breaths as they clung to their seapony companions who guided them to shore.

Next Chapter: Chapter 20 Estimated time remaining: 3 Hours, 2 Minutes