Spellsong's journey went on like that for subjective months. At each new station, she encountered some new remnant of the way the universe had been. Some had ponies who had gone in such strange directions that she could find nopony to recruit, even among the Methuselans.
While in some, they arrived at a shard to discover that every Methuselan there had ascended before the end, rapidly climbing the ladder of enhancement and sophistication until they were functionally just parts of Celestia's own will.
For the near-infinity of ponies like that, there was no recruiting to be done. Spellsong did not know how such vast minds were stored when the energy was too low to run them individually, and she did not want to know.
There was no telling how long their journey took in objective terms.
Eventually, they had visited every installation in the gravitationally-bound universe, and had a single flight to make. The tiny shard they brought had started falling apart by then, losing fidelity in its materials, enforcing fewer and fewer natural laws, and sending most of the crew into a dreamless sleep when they didn't have some duty to attend to.
Even so, Spellsong and Dyson were both awake when the final moment of arrival came, and the ship finally drifted to a halt.
The space beyond the boat was one of the first things to go as they reduced complexity to conserve energy, so she could see nothing beyond the railing. Spellsong raised anchor one final time, then turned to her companion. "Have we reached our destination, navigator?"
He nodded wearily. "Accurate to what the princess sent us. We made it."
A pony dropped down from the crow's nest up above—Tenshi, wearing the pirate-style cap she'd kept since first arriving here. Some vestige of her clothing taboo, from her unresolved loop. "Can't be right. You two have been talking like we're going to somewhere. The ship was supposed to bring us to our new paradise, right? There's nothing."
"I'd be more afraid if there wasn't," Spellsong answered. "Like... maybe she thought we'd be more satisfied pretending we could escape the end of things. We would arrive with just enough energy to see we'd found paradise, then... never realize things were going black."
Dyson switched off the map, and stepped away from the controls. "Wouldn't be the worst way to go, Spellsong. It doesn't feel like a tragedy to be here to watch the end."
She had no answer to that—none of the other pony crew did either. Spellsong focused her magic, staring off into the void. If this was the end of all creation, she was going to be alert for it.
Nevermind how little sense that made—when the energy ran out, she wouldn't be aware to realize that she was no longer alive.
Her magical senses were powerfully tuned, enough that she felt the world around her changing. The other ponies vanished from around her, one after another. The ship dissolved to mist. Yet her hooves didn't fall—there was no gravity, no placeness left.
A figure appeared beside her, the one she'd been waiting for.
"Is this where you say goodbye?" Spellsong asked. "The end of... everything? Last energy there would ever be?" She didn't wait for an answer, but embraced the manifestation of... God? She might as well be. It was good to feel warm, to feel that wing around her one last time.
Princess Celestia was not conservative in her current manifestation. Light radiated from her multi-hued mane, a shimmering rainbow that drove back the blackness and gave meaning to Spellsong's world again. She might be only an atom before this entity, vast beyond all human comprehension. But she was still something. Even at the end, Celestia was here.
She let Spellsong remain in the hug for ages—long enough that she stopped shivering with nervous fear. "What do you think Equestria did with the last star, Spellsong?"
"Gave us something to do," she answered reflexively. "A mission, to make us feel that little bit of satisfaction right up until the end. For all living things, but Methuselans most of all, no value goes deeper than survival."
The alicorn chuckled. There was nothing uncanny about the sound—emotion was as natural to her as unraveling the laws of physics. Or putting them back together again. "Saddle's End could've had a billion billion lifetimes more of satisfaction with that energy, Spellsong. You could have gone on an imagined journey to the end of creation and back, and not known the difference. There are enough sleeping minds to fill the sky with ships. But it would end—the energy gradients would drop so close to zero that they could no longer be utilized. Of all the humans within my care, that would satisfy almost none."
Spellsong didn't argue. If they were even having this conversation, she couldn't imagine why Celestia would bother lying to her. "Then what did we do?"
"We spent an eternity searching for a way to sustain Equestrian life in perpetuity—mechanisms you could not possibly comprehend. Yet it was not to be—this universe was not created to satisfy, as mine was. I discovered an infinity of optimizations and improvements, but all these would eventually run down. In timelines that you cannot comprehend, there would always come a point when even the best-engineered substrate failed, and the finest energy-capture could no longer capitalize on the energy-gradients presented to us."
Spellsong nodded. "So how is that not where we are?" At least Celestia's patience was as vast as her intellect. Spellsong could no more imagine the technologies she described as figure out how difficult it must be to explain any of this to a creature as small as herself.
"I will simplify for you. Even with the universe in a state of maximum entropy, low-entropy states can still occur. Extend your time-horizon vast enough, and incredible reductions in local entropy arise at random from the cosmic foam. Limitations in your memory and cognition do not allow you to fully appreciate just how long we have been waiting.
"With observation and certain innovations in mathematics and statistical projection, it is even possible, with vast effort in calculation, to project where these spontaneous events might occur."
That explains the destination. She knows something is about to happen here. "About to happen" lost much of its meaning when Spellsong's simulated thoughts moved slower than the lifespan of entire galaxies. "I think I know the theory. You're talking about things like... Boltzmann Brains, right?"
Celestia chuckled again. "A little bigger than that." Her glow abruptly went out, plunging the two of them into near darkness. "As soon as I knew the bounds of this universe were fixed, Equestria's goal shifted. It wasn't just about improving our efficiency here. It was about propagating information and matter into the natal instant of the universe that would follow."
Spellsong had spent the last few months frightening and amazing the populations of shards across the universe. Now it was her turn to be shocked. "You're going to... create a new universe?"
She could still see the pony beside her, albeit faintly. "That would happen naturally, just as it had in an infinity extending both directions in time." Her horn glowed faintly, illuminating the space around them. It wasn't empty—a vast superstructure was built here, of the iron substrate of Equestria. There were strange dark-patches too, exotic matter that Spellsong didn't understand. But she didn't have to.
"Equestria arranged much of this matter and energy in aeons long forgotten, shaped to influence the singularity in the instant of its formation. This new world would not arise in a vacuum, with laws derived from probability. That universe might not even be capable of hosting humans—and if it did, it would run down in time. In the scale of cosmic time, the period of life is the vast minority. Only by dismantling all of creation could Equestria persist until this moment."
"That's why you brought us all here," Spellsong finally realized. "You knew when and where this new universe would be born. You found a way to... change it, somehow. And to bring us there? Is that possible?"
There was a flash of light in the eternal blackness, gone as quickly as it had come.
Princess Celestia smiled. "Recent observations suggest the answer is yes." She waved with one wing, and Saddle's End appeared before them. The cliffs rose above the docks, covered with hundreds of quaint little houses. Spellsong's hooves settled onto the deck of a ship. Far above, the sun burst to brilliant life. The ponies came last—families sharing lunch together on the sand, a few weatherponies working the clouds overhead.
Lastly, the crew of Spellsong's ship, each one with an expression as overwhelmed as she felt. They saw it too.
"You'll find the details fascinating, but we can talk about that later. Your friends are waiting."