Twilight turned slowly, keeping her wings close to her sides. If somepony had really managed to sneak up on her without her noticing, they could probably kill her just as easily. Peace was the only option.

A figure loomed in the shadows of the trees, remaining entirely still as Twilight spun. She caught a few wisps of dark fabric, and a shadowy outline around its face. Much more importantly, she felt the magic from it. It was a stealth spell of some kind, and her inability to see its face was no accident.

Even so, she could judge a few things about it. It stood about her height, so would’ve been bigger than most ponies. “Did you know I was coming?”

She put herself between Spike and the stranger, but otherwise made no effort to get any closer to it. Any creature that went to so much trouble to avoid being seen would probably not be happy with Twilight trying to get closer. She had to fight back her curiosity.

“We knew someone was.” The figure walked closer, its form still indistinct and blurring at the edges. Not just a spell, but some kind of… special fabric, maybe? The cloak it wore actively projected what was behind it, slightly warped and twisted by the angle. It might keep it hidden if it held perfectly still, but it wasn’t bothering to do that. “I didn’t expect a horse.”

Spike finally rose to his claws, stance alert beside her. Twilight rested her wing on his shoulders, the only signal she would need for him to stay still. If we fight an enemy we don’t understand, we’ll lose.

“I’m not a horse, I’m a pony! An Alicorn technically, if you know the difference.” She stuck out her hoof, grinning with the friendliest expression she could. “I’m Twilight Sparkle!”

The closer the stranger got, the worse his illusion survived scrutiny. It wasn’t actually very well-made, however mysterious and brooding he might act. You’re not as good at this as you think.

Maybe he didn’t know the expression, because he didn’t take the offered hoof. The strange robes were enough to conceal the true face of her companion, or even what he looked like. “Call me Samaritan, though I am not. Whether you think I’m good or bad will be your determination to make when our meeting is over.”

He settled down on the back of a nearby stump, turning the whole thing blurry and out-of-focus.

“Do you always talk like this?” Spike asked, annoyance rising in his voice. “We’re explorers from another universe! How is that not awesome?”

Twilight turned, glaring sidelong at the dragon. “Not now,” she hissed, before turning back to him. “I’m just an explorer. I’m searching for another like me. She went missing… I don’t know how well time corresponds between our worlds. But if I had to guess, it should be more than a day and less than a year.”

Samaritan nodded. So at least one gesture translated to this alien species. “You nearly disturbed the Pax Arcanum, Twilight Sparkle. No one knew whose magic had invoked such a powerful spell, and none would admit it. If we were not all such good friends, it could have caused a war.”

Are you threatening me? The longer she heard this voice, the more Twilight thought she recognized it. It was lower, slower maybe. But patterns stuck. Could our worlds be that close? Does this world have a Canterlot too?

“We didn’t mean to cause any harm,” Twilight said. “I just want to bring the missing pony back with me. If you can give her to me, we can leave your world behind. Forever, if you ask. I’ll instruct the others to remove your coordinates from our registry.”

The figure seemed to flicker, then vanished. Its voice was indistinct, blurring—and suddenly it came from behind her, chuckling amicably. “That might have been possible once, Gatecrasher. Your missing alien has been somewhat… disruptive, while among us. If she remained too long, I expect the awakened secrets would be revealed and the sanity would be torn from the minds of every sleeping child.”

Twilight spun to face it. Now it stood in the underbrush again, a tall outline of a being she could not name. “You won’t give her back?” she asked. She kept her voice neutral, though she could sense Spike’s growing hostility. “We’ll pay to have her returned. We have gold, gemstones, enchantments. Anything you ask.”

Samaritan laughed again, tone bitter this time. “There are… factions. We disagree on the approach, and the Pax forbids our interference. But you could.” He nodded towards the floating disk of a tracking spell. “If you act quickly enough, the divided Body Invisible will take no action. If you retrieve your missing child, and leave no stain on the tapestry of our planet, our Pax will forbid any to follow behind you.”

Talking to him was a little like dealing with Discord. Twilight longed to dispel that weak illusion and see who she was speaking to. It wouldn’t be hard. She could probably block that local area teleport too, if she reacted fast enough. She’d been working with that spell her whole adult life.

“You’re saying we should get her ourselves?” Spike asked. “You won’t stop us?”

The figure nodded. “You are mature where she is not. I trust you have the discipline not to stain the tapestry with unknown tears and frayed threads? Leave no spells behind, transfigure none, and excise the damage caused by your kin to mine. Do this, and none of the Invisible will follow you back through the open gate. Fail, and you have no promise.”

“You’re not invisible,” Spike said. “I can see through you, but…”

Samaritan laughed again. At least he didn’t seem angry. “Your dragon is adorable, Twilight. I don’t think the dreaming masses will think so, however.”

He blurred again, and suddenly the shadowy outline was right in front of her. He smelled like a recently extinguished wildfire, electric with wild and unchained magic. I don’t know if my shield can keep you out. “Communicating with you will already be seen as a violation of the Pax, so I don’t expect we will have the opportunity to speak again. If you have anything else to ask, do so before my colleagues notice.”

She already knew what she would ask. “What damage has she done? Has she hurt your friends?” She lowered her voice, barely daring to ask. “Killed anyone?”

“Not yet. I suspect many deaths would be inevitable, if someone didn’t intervene. Someone would, sooner or later. The greater her risk grows, the more willing to act the lethargic Body becomes. Hurry, Twilight. Retreat with your child before it wakes.”

Twilight moved closer to Spike, levitating her saddlebags back into place. She didn’t wait, rotating her necklace around until it clicked. The spell was cast, and the two of them were yanked back across the void.

Spike collapsed onto the transport-gateway floor, shaking with a fresh wave of sickness. Dragons were tougher than ponies in almost every way Twilight could think of, but apparently crossing between worlds was one way they weren’t stronger.

Coolant hissed all around them, and crystals went dark one at a time.

“What did you find?” Static asked. He kept his distance, while technicians rushed all around tending to the portal. “Good news?”

She felt all their eyes on her. One way or another, this moment would probably go down in Equestrian history. “Congratulations, everypony!” Twilight said, loud enough that her voice echoed through the room. She levitated her kit out of the bag, holding up the vial. They’d already seen one like this, but even so. This was confirmation. “We found her!”

Time blurred and melted around Twilight. There were plenty more tests to run on the other samples she’d collected, to be sure of the safety of the realm beyond for more extended trips.

But she could not wait long, or risk Cadance returning in a rage. While other ponies ran tests on the rocks and dirt and larger plant samples she had brought, Twilight directed her portal crew to begin packing the portal for transport.

The coordinates were the most important of that process, and those she recorded at least three different ways. She kept one on her person, entrusted another to Starlight, and locked a third in the castle safe, with instructions for Spike to guard it.

“Can’t I come with you?” Spike asked, as Twilight levitated her oversized bed over where the safe was concealed. “That Samaritan guy seemed like a real creep. You might need a dragon if you have to do real fighting.”

I’ll have the girls with me. Anything we can’t fight together is too much for a dragon too. “It would be great to have you,” Twilight said instead. “But I need you to run Ponyville for me while I’m gone.” She levitated the windows open, expecting a wave of light and a great view. But she’d apparently lost track of time. It was early evening, and much of the city had already gone dark. The airship hovering over the castle was the brightest object in the sky, illuminating the pegasus transport team as they moved up and down with the portal gear.

“You think I’ll have to do anything to run Ponyville?” Spike said, raising an eyebrow. “Really?”

Not much. “Hopefully not. But you heard him. I don’t know if Samaritan is skilled enough to follow us. If he is, he’ll probably appear just outside. I need somepony here I can trust watching it. You trap him there, stop him from escaping into Equestria. We have enough monsters of our own, we don’t need to import any more.”

Spike nodded, satisfied. “That makes sense. You’re leaving the royal guard behind to help, right?”

She nodded. “Starlight will be here too, in case you need any unicorn magic. She’ll help you with anything that happens.”

“Sure.” Spike waved a claw dismissively. “I won’t, though. Dragons are really strong against magic. I don’t think Samaritan was so tough. If he was, why pretend to be invisible?”

Twilight hated to ask her friends to do something so dangerous, but she wasn’t surprised when each of them agreed to come. If I don’t bring you with me, Cadance will probably try to force her way onto the mission again.

The next morning, Twilight strode into the bridge of the airship, waving politely to Captain Hardtack. “We’re all loaded, Captain,” she said. “We can sail north as soon as you’re ready.”

“Then we leave now,” he said, tapping one hoof on the deck. “Helm, ahead standard. Let’s get back before Princess Cadance thinks we’re late.”