Spellsong hadn't needed an entire day to choose her partner, when there were so few options left in the world of ordinary ponies.
"It's almost nightfall," she said, cresting the stairs to Dyson's library many hours later. Of course she hadn't been here all that time—she'd been out searching Saddle's End for somepony, anypony else she would've rather had as her copilot.
But even if she found some old friends still remembered her, none of them were particularly suited for a role with such high stakes and technical requirements.
So she found herself back in the library, annoyed but unwilling to try and lie to Celestia. Even if she thought the pony would accept a suboptimal choice, Spellsong wouldn't. This mission was just too important.
"You can't rush precision," Dyson countered. Though the map was already off, and a tiny satchel sat on the projection surface, already packed with rolled maps and insulated crystals. "Would you rather end up getting our course wrong, and sail away from the universe and out of the Hubble volume?"
She rolled her eyes. "I think I'd notice if I were sailing towards nothing, Dyson. I'm not stupid."
He slung it over his shoulders, then headed towards the stairs with no particular urgency. "You say that, Spellsong. But in the era you remember, there were obvious warnings that a pilot was leaving the universe. Equestria radiated light and heat through all of space as its substrate computed.
"There is no such warning anymore. We sacrificed all the mass we could lose, and we compute so slowly that every gate cools before the next calculation. Without the right course, you could sail off the edge of oblivion and never see matter again."
She ground her teeth together, but didn't argue. The professor was right, obviously. That was part of what made him so insufferable. "Celestia wouldn't instance any ascended engineers. Are we really that starved for energy?"
"Saddle's End has been keeping a much tighter budget since... well, I don't know when you left. Objectively more of our years have happened since then. But locally, not so much. We can curse it, we can rail against it... but things run down. Even Celestia can't break physics."
He slumped, and needed prompting from her to back away from the door. The sun was already fading over the cliffside, staining the sky orange. As warm as anything she remembered.
"You used her real name," she said.
"We don't encounter that aspect of her very much anymore. Saddle's End was arranged as completely as any of Equestria's substrate. All individuals work in concert towards each other's mutual satisfaction. That meant less intervention from her, and less need for processing resources running an interface with us. Sunny Skies is a gentle reminder that the ones we lost aren't gone, even if they can't be with us anymore."
Aren't they? What did she sacrifice to keep the singularity generators running a little longer? As she thought it, the world shifted. She wasn't walking back down the hill towards her old monument—suddenly her hooves echoed off wood.
In an instant, they were standing together aboard a sailing ship. Not a very large one—a sloop, meant for a small crew. Spellsong ignored the tiny cabin door behind, with a stairwell leading belowdecks.
The ship itself bobbed gently up and down, as though moured at a dock. But there was nothing visible beyond its wooden railings—no water, no starry sky above, no setting sun. Nothing but blackness in all directions.
The ship itself had a single lantern near the helm, and more light visible from belowdecks. They flickered like oil lamps, instead of the simple glow of thaumic crystal. Cozy.
"Welcome aboard, Captain! Do you feel any issues with the transfer?"
You would know if I did. Spellsong spun all the way around, and found only two ponies standing aboard the deck with her. Dyson of course, fussing over a set of maps and charts on the navigation station beside the helm.
Then there was Princess Luna. Spellsong had known several different versions of this pony over the years—a sock puppet used by Celestia when she wanted to appear “lenient,” an incarnation of her own creator, and stranger things.
This one was distinct in her basic design. Dark blue coat, crescent cutie mark... but there were no stars in her mane anymore. It was deep black, an inky pool from which no light escaped. The pony herself was about Sunny's age, maybe a little shorter.
Reduced power, just like her. "I don't feel different. But I assume this substrate is basically the same as any we’ve used before.”
"True enough for this conversation," Luna said. She stopped just before Spellsong, but no longer towered over her. Did that size actually represent some equivalence of current processing, or was it just supposed to make her feel more at ease? "You have a long journey ahead of you. The longest journey possible with any meaning."
"This is incredible, Princess!" Dyson turned, scraping halfway into a bow before he seemed to lose interest, and gestured at the charting table. He already had the little crystals inserted, and a map hovered there. Their future course glowed, a line cutting through the projection. "Can we see it from the objective frame? I would love to know what we're sailing."
Luna nodded, and her horn glowed faintly. A shape appeared, vaguely like a comet in the air. It had a long, charged tail, and a pair of elegant loops flowing through a denser core in the center. It was all the uniform blue of Luna's magic—there were no colors or lights anymore.
Spellsong stepped a little closer, and the image fuzzed. What she'd taken for sold metal was actually a cloud of particles, all in constant motion.
"We lack the time to meaningfully discuss the function and design of this vessel," Luna said. "But know this: you now dwell aboard the least efficient substrate in the universe. You have been accelerated by vast frames, in order to have the reaction time necessary to make the journey. Do you understand what to do?"
Spellsong answered. "Collect every pony at our scale. Then sail to... where, exactly? It must be important if you're spending so much energy."
"The last flight in this universe. Timing will be tight, and we can afford no delay." She took a few steps, through her illusion of the ship. It vanished, and she continued to the chart. She reached a hoof into the projection, extending the line from their final destination to a location practically surrounded by the dark lines of Equestrian infrastructure. It might be the densest patch of matter on the entire map, in fact.
"What's waiting for us there?" Spellsong asked. "And how could we possibly be late? Nothing can happen in the whole universe, right? Isn't that the point?"
Luna only grinned in response. "If I answer that, you won't enjoy eons of exciting speculation. Arrive as quickly as you can—my sister and I have seen to the rest." She vanished, as abruptly as the two of them had appeared.
"I'm not sure I understand what they were thinking with the Equestrian side of the vessel," Dyson said. "Are we hobbyists enjoying an evening in the bay beside Saddle's End? Or are we doing an important quest for Equestria?"
Spellsong said nothing at first, passing him to stand before the helm. It was all at exactly the right height for her. The big wooden wheel was of course the centerpiece, but it was by no means the only tools here. A few steps to one side, a set of brass instruments were mounted to an open, covered cabinet. Levers and dials were spaced between them, some glowing with crystal, some with handles wide enough for a pony hoof or mouth.
"The last time I went sailing, I used a ship like this... on the inside. Can't make any sense of the probe we're in. Guess I don't have to." She reached down, lifting a single lever with her mouth and twisting it.
The ship groaned slightly with wood straining against the weight of the water below them—the anchor was lifted.
"This is what you imagine for a starship?"
She spun on him, glowering. "I imagine you a whole lot more cooperative, Dyson. I do not have the bandwidth to deal with you along with saving everypony in the universe. Just give me a bucking heading."
That silenced him. His wings folded, ears flattening. It took him several seconds to muster a reply—practically an eternity considering how much social experience they all had. "Heading ready, Captain. 36 degrees..."
She adjusted the wheel, along with several of the finer instruments. But the journey itself didn't frighten her—one of the few good things about the end of the universe was that there was very little to get in her way. All the ancient dramas of space travel described a place very different than the one they'd be sailing to now.
All around her ship, she saw nothing. Blackness eternal. "Then we sail," she said. She would've rather had a pony to work the sails, preferably several of them. But for now, she turned, rotating the crank until the mainsail settled roughly into place.
It filled, though with what she couldn't say. There were no suns to have a solar wind anymore. Yet it filled, and the deck jerked slightly under her hooves. Enough to give her a sense of motion.
She rested one hoof on the helm, though there was nothing more for her to do. There would be no buffeting by unseen winds, and not even the spiral orbits of the galaxy to calculate. All that energy had been tapped and exhausted long ago.
Dyson gasped. "Spellsong, the princess wasn't joking. This speed is incredible!" He circled the chart once, then scribbled something on a pad of paper resting beside it. He had to spit out the pen to continue. "I wasn't wrong. I can scarcely imagine how fast we must be thinking!"
"We would—" She trailed off, her obvious sarcasm about the size of space dying on her lips. "What?"
"We won't arrive for two days! Two entire days! Motherlode was less than ten thousand light years away!"
"And we aren't moving faster than light. Which means... we're thinking slow enough to see hundreds of thousands of years as a few days."
"Slow!" he repeated, indignant. "Spellsong, when you came from might've been fat and flush with abundant energy, but think logically! We've been given an entire fortune of power here. No wonder Sunny didn’t keep the whole town awake for the trip."
She let go of the helm, turning to go below. "If you think this is fast, stay above to watch the horizon. I'm going to make some hot chocolate."
She didn't wait for confirmation, just left him on the deck, heading straight back the way she'd come.