Ungula

"Who and what are you and how did you get in here?" Cadance was quick to ask.

The wrinkly hippogriff thing obligingly paused in their questioning to answer, swiveling their head to look directly at Cadance. "I am Now Turn Thy Gaze Ahead. Wandering umbrum extraordinaire. And, I walked."

Cadance was not terribly satisfied by this answer, as Now Turn Thy Gaze Ahead had still popped up out of nowhere in her garden and started asking questions about experimental technology. But at least she knew what they were now. And had several dozen more questions as a result.

The Fire of Friendship's crew was visibly even less satisfied by this answer. Most of them were still reeling from the sudden appearance and deferring to Cadance in how to handle it.

Rainbow Dash was not doing that. "What kind of name is that? And what the heck is an umbrum? And why are you here?"

Now Turn Thy Gaze Ahead turned to look directly at Rainbow Dash. "It is my name-story. You may call me Gaze for short if name-stories are too long for your tongue. I do not want to explain what an umbrum is, it is a long story and you can just ask your princess here about most of it. And I am here because those tags on your collars caught my attention and now I want to know more about that fire and the principle behind the Amity reactor."

Rainbow Dash was not satisfied, and got right up in Gaze's beak. "And what's–"

Rainbow Dash disappeared with a pop.

"I'll bring her back when we're done. Please tell me about your friendship fire reactor thing and the principles behind it."

It was dark, and Rainbow Dash didn't know why.

("...and the principles behind it.")

"Hey! What'd you do to me!"

She could still hear them. They, evidently, could not hear her.

As her friends protested her apparent disappearance, Rainbow Dash took stock of her situation.

("Why do you even want to know about that?" she heard Twilight ask, voice trembling but holding it together.)

Sound wasn't obscured, she could find her friends by their voices just fine. She should be able to find Gaze by their voice too, then.

("Because it's something we didn't know about magic? I think Web of Truths was working on a theory like that, but they didn't make it. Who knows, maybe it would have made the difference.")

Rainbow Dash tackled where Gaze's voice was coming from. There was nothing there.

("Now answer my question. You do want her back, right?")

("Th-the Amity Hypothesis states that friendship is literally magic. Magical fields arise from the bonds between sapient beings, with more and stronger bonds creating bigger and stronger magical fields.")

Dash followed Twilight's voice, this time, and gave her a nudge. She was right where it sounded like, but she didn't seem to notice the nudge at all.

("So it's not the number of beings, but how interconnected they are? Fascinating… That would explain quite a few observations made during the later days of our time in the Void, when we were all falling apart.")

Gaze must be throwing their voice somehow, or something of the sort, Dash concluded.

("That's what we think, a-and experimental data seems to bear it out. The Fire of Friendship has a stronger magical field than any starship before it, because its crew was specifically chosen for our strong bonds with each other.")

Rainbow Dash was the most pegasussy pegasus to ever pegasus. Sound went through the air, and that was meteorology. She didn't have the hearing of a thestral, but even they couldn't feel the atmosphere like she could.

("Your whole ship is powered by nothing but friendship, then?")

There. A tiny current of warm air that started and stopped with Now Turn Thy Gaze Ahead's voice, on the other side of the patio from where it sounded like it was coming from. It was miniscule, it barely affected the atmosphere at all, if it wasn't so irregular she'd never have found it. But she was Rainbow Miriam Dash, and her friends needed her.

("If the hypothesis is correct, the amiable force could be codified as a fifth fundamental force of the universe, allowing us to finally place where magic fits in with the standard model of physics. So yes, it's powered by friendship.")

("Mm, that always was a tricky–")

Rainbow Dash pounced.

"–problACK!"

The illusion broke, and she could see again. Her friends turned from where Gaze had seemed to be, now able to see Dash and Gaze both.

Now Turn Thy Gaze Ahead felt just as wrinkly and leathery as they looked. It was kind of gross.

"Kick its ass, girls!" Rainbow shouted.

"Whoop, that's my cue to leave! Good talk! We should do this again sometime!"

As they all charged, Now Turn Thy Gaze Ahead contorted out of Rainbows Dash's grasp and seemed to split into around a dozen of themself, each of which took wing and flew in a different direction. Bolts of magic flew through them as if they weren't there, revealing them to be illusions.

None of them were the real one, of course. Gaze was gone.