“Maybe Fillory doesn’t have an End,” Quentin said one night, as they were tucking into their increasingly meager and unappetizing rations.

“What, like it’s infinite?” Josh said. “Or it’s a sphere, like Earth? God, I hope it’s not that. What if we end up back at Whitespire again? Man, I’ll be pissed if all we’ve done is find the Northwest Passage or whatever after all that.”

He licked his fingers, getting the extra salt from a salt biscuit. He was the only one who didn’t seem overawed by the situation.

“I meant more like a Möbius strip. What if it’s all one side, and no edge?”

“I think you mean a Klein bottle,” Poppy said. “A Möbius strip still has edges. Or one edge.”

“You mean a Klein bottle,” Julia confirmed.

Nothing like having a demi-goddess around to settle an argument. Julia didn’t eat anymore, but she still sat at dinner with them.

“Is it a Klein bottle? Do you know?”

Julia shook her head.

“I don’t know. I don’t think so.”

“So you’re not omniscient?” Eliot said. “I don’t mean that in a bad way. But you don’t know for sure?”

“No,” Julia said. “But I know this world has an End.”

They all woke up early the next morning when the Muntjac ran aground.

It wasn’t like they hit a wall. It was more gradual: a distant grinding sound, gentle at first, then louder, and then suddenly urgent, bone on bone, ending with everything on board, people included, slewing gently but firmly into the nearest forward wall as the ship came to a complete stop. And then, ringing silence.

They all came up on deck in their robes and pajamas to see what had happened.

The stillness was uncanny. All around them the sea was flat and glassy as a coat of fresh varnish. No wind blew. A fish jumped, maybe a quarter-mile away, and it sounded as loud as if it were right next to them. The sails hung slack. The slightest vibration sent circular ripples gliding away toward the horizon in all directions.

“Well,” Eliot said, “that tears it. What do we do now?”

It crossed Quentin’s mind, as it had presumably crossed that of the crew, that they had long ago passed the halfway point of their supplies. If they couldn’t go forward they would die on the way back. Or just die here, marooned in a desert of water.

“I will speak to the ship,” Julia said.

As she had even when she was still human, Julia meant what she said and said what she meant. She went down to the hold, to the heart of the ship, where the clockwork was, knelt down, and began to whisper, stopping now and then to listen. It wasn’t a long conversation. After four or five minutes, she patted the thick base of the Muntjac’s mast and stood up.

“It is settled.”

It wasn’t immediately clear what had been settled, or how, but it became apparent. They floated free of the bottom and began gliding forward again as if nothing had happened. Quentin only figured it out when he happened to look back at their wake. Enormous old planks and beams and other assorted carpentry were bobbing and turning in the water behind them. The Muntjac was making herself smaller, rebuilding herself from the keel up and discarding the extra wood as she went. She was giving up her body for them.

Quentin’s eyes smarted. He didn’t know what sort of being the Muntjac was, whether it had feelings or whether it was just some kind of mechanism, an artificial intelligence constructed out of rope and wood, but he felt a surge of gratitude and sadness. They’d asked so much of it already.

“Thank you, old girl,” he said, just in case it, or she, could hear him. He patted the worn railing. “You’ve saved us one more time.”

The shallower the ocean got the more the Muntjac had to alter herself. Quentin told the crew to bring up the sloth, who permitted herself to be slung from a yard, blinking and yawning in the open air. They emptied the cabins and the hold and piled up everything around them on deck.

Banging and groaning sounds came from below, deep in the ship’s guts. Quentin watched as first the Muntjac’s high, proud stern dropped into the water, then its bowsprit and its entire forecastle. At around four o’clock in the afternoon the mizzenmast toppled over into the water with a huge splash and was lost astern. The foremast went that evening. They slept on deck that night, shivering under blankets in the chill.

In the morning when they woke up the sea was shallow enough to wade in, and the Muntjac had become a flat single-masted raft. Its hull was completely gone; only the deck was left. The ocean mirrored the cloudless dawn light, making an infinite plain of smoky rose. When the sun boiled up over the horizon it was immense—you could see its corona curling around its bright, unbearable face.

At noon they ran aground again—the front edge of the raft crunched to a stop on the sandy bottom. That was it; the Muntjac was going no farther. She had nothing more to give.

But by now they could see that their journey did in fact have a destination. A low, dark line had materialized out of the distance, running the full width of the horizon. It was impossible to guess how far away it was.

“Looks like we’ll have to walk,” Quentin said.

One by one Quentin, Eliot, Josh, Julia, and Poppy swung over the side and dropped into the water. It was cold but shallow, not even kneedeep.

They had already set off when they heard a splash behind them. Bingle had climbed over the railing—he was coming too. Evidently he did not consider his bodyguarding duties fully discharged. And Abigail the Sloth: he was carrying her piggyback, her long arms around his neck like a fur wrap, her claws hooked together in front of him.

The loneliness of the scene was beyond anything. After an hour the ship was virtually invisible behind them, and the only sound was the steady soft slosh-slosh of their footsteps. Sometimes the mouthless fish came and bumped harmlessly against their ankles. The thin water was easier to walk through than regular seawater would have been; it put up less resistance. Julia walked along on the surface as befitted a demi-goddess. No one spoke, not even Abigail, who was almost never at a loss for words. The ocean was smooth as glass to the horizon.

The sun was hot on the tops of their heads. After a while Quentin gave up staring at the horizon and looked only down, at his familiar black boots taking step after step after step. Each step took them closer to the end of the story. They were going to finish this. Something could still go wrong now, probably, but he had no idea what. He could gauge their progress by the gradual shallowing of the water, from his calf down to his ankle and finally to a thin film of water that splatted underfoot. The sun was low in the sky behind them. Far off to their right a single evening star had appeared, with its twin shimmering below it in the water.

“Let’s hurry,” Julia said. “I can feel the magic going.”

By that time the wall in front of them was very clear. It might have been ten feet high and was made from old, thin bricks—it looked like the same bricks they’d used to build the wall in hell. They must have used the same contractor. It stood at the back of a thin gray sandy beach that stretched off to the vanishing point in both directions. A huge old wooden door was set in it, bleached and worn by time and weather. As they came closer they could see that the door had seven keyholes of different sizes.

On either side of the door were two plain wooden chairs, the kind of old chairs that might have gotten exiled to the porch because they were too shabby for the dining room, but were still too good and sturdy to throw away. They didn’t match; one of them had a wicker seat. In the chairs sat a man and a woman. The man was tall and thin, fiftyish, with a stern, narrow face. He wore a black dinner suit, complete with tails. He looked a little like Lincoln on his way to the theater.

The woman was younger by a decade or so, pale and lovely. As they stepped onto dry land she raised a hand to greet them. It was Elaine, the Customs Agent from the Outer Island. She looked a lot more serious than she had the last time he’d seen her. She had something in her lap: the Seeing Hare. She was petting it.

She stood up, and the hare jumped down and skittered off down the beach. Quentin watched it go. It made him think of little Eleanor and her winged bunnies. He wondered where she was, and who was taking care of her. Before this was over he would ask.

“Good evening,” Elaine said. “Your Majesty. Your Highnesses. Good evening, all of you. I am the Customs Agent. I tend to the borders of Fillory. Borders of all kinds,” she added pointedly, to Quentin. “I believe you met my father? I hope he didn’t inconvenience you too greatly.”

Her father? Ah. More fairy tale. He supposed that fit together neatly.

“Bother, it’s almost time,” the man said. “The gods are finishing their work. Magic is almost gone, and without it Fillory will fold up like a box with us in it. Do you have the keys?”

Quentin looked to Eliot.

“You do it,” the High King said. “It was your adventure first.”

Eliot held out the ring with the seven keys, and Quentin took it and walked over to the big wooden door. He kept his back straight and his gut sucked in. This was the moment, he thought. This was the triumph. People would tell this story forever. Though they might leave out how melancholy the twilit beach seemed, like all beaches in the early evening, when the fun is over. Time to slap the sand off your feet and pile into the station wagon and go home.

“Smallest to largest,” said the man in the tuxedo, sternly but not unkindly. “Go ahead. Leave them in the locks as you go.”

Quentin slipped each one off the key ring in turn. The first, tiniest lock turned easily—you could feel a mechanism of fine, well-oiled gears meshing and interlocking and turning inside the door. But each successive key put up more resistance. The fourth one was set so high up that he had to stand on his tiptoes to turn it. He could barely budge the sixth, and when he finally got it going, his fingers bending back and his knuckles white with the effort, light flashed inside the keyhole, and it spat out sparks that stung his wrist.

The last one wouldn’t turn at all, and in the end Quentin had to ask Bingle for his sword, which he stuck through the metal ring at the end of the key and used as a lever. Even then the man in the formal suit had to get up from his chair and help him.

When it finally gave and began to move, it was like he’d fitted a key into a hole in the hub at the center of the universe. Together he and the man put their backs into it—Quentin’s face was crushed into his shoulder. His suit smelled faintly of mothballs. As the key turned, the stars turned overhead. The whole cosmos was rotating around them, or maybe it was Fillory that was turning, or maybe there was no difference. The night sky spun above them until the day sky replaced it overhead. They kept turning, and the day sky sank below the horizon again, and the stars rushed back out.

Full circle. They were back where they started. There was a deep click that seemed to echo forever, the sound bouncing off the outer walls of the world, a bank vault opening in a cathedral. The door swung slowly inward. Behind it, through the doorway, was empty space, black sky, stars. Quentin took an involuntary step back. Everybody on the beach, even Bingle, even the sloth, let out a breath they didn’t know they’d been holding.

“Well,” Elaine said shakily. She was flushed, and she even laughed a little. “I have to admit, I wasn’t sure that would work.”

“Did it work?” Quentin said. He looked around for a sign that things were different. “I can’t tell.”

“It worked.”

“It worked,” Julia said.

Somebody caught Quentin from behind in a huge bear hug. It was Josh. They fell down on the chilly sand together, Josh on top.

“Dude!” Josh yelled. “Look at you! We just saved magic!”

“I guess we did.” Quentin started laughing, and then he couldn’t stop. It was all over. Magic wasn’t going to leave them after all. They had their own magic now, and it was safe. Not just in Fillory but everywhere. Nobody could take it away from them. Probably a little more dignity befitted the Saviors of All Magic, but fuck it. Poppy whooped and piled onto them too.

“You losers,” Eliot said, but he was grinning his crazed, jagged grin. “We should have brought champagne.”

Quentin lay back on the sand and looked up at the darkening sky. He could have fallen asleep right then and there on the sand, and slept all the way back to Whitespire. He closed his eyes. He heard Elaine’s voice.

“If you like,” she said, “you can go through it.”

Quentin opened his eyes again. He sat up.

“Wait,” he said. “Really? Through the door? What’s back there?”

“The Far Side of the World,” the Customs Agent said simply.

“The Far Side,” Eliot said. “We don’t know what that means.”

“I should explain,” she said. She settled herself back on her chair. “Fillory is not a sphere, like the world where you were born. Fillory is flat.”

“So not a Klein bottle?” Josh said.

“I have so many questions,” Poppy said. “Like how does gravity work?”

“As such,” Elaine went on, ignoring them, “Fillory has another side. A verso, if you will.”

“What’s on it?” Quentin asked. “What’s over there?”

“Nothing. And everything.”

When this was over Quentin was ready for a long vacation from gods and demons and all their cryptic utterances.

“There is another world there, waiting to be born. A world for which Fillory was in a sense merely a rough draft. You might make an analogy: the Far Side is to Fillory as Fillory is to your Earth. A greener place. A realer, more magical place.”