Sofia went in first, then Tick, then Paul, who closed the door behind him.

The inside was a perfect cylinder, completely covered in thick, rubbery padding that was a burnt-orange color. Along the bottom, a bench protruded from the walls—also covered in soft padding—making a circle for the passengers to sit and stare at each other.

“This is a train?” Tick asked no one in particular. An uneasy feeling crept into his bones.

“What do we—” Paul began, but was cut off by an electronic woman’s voice coming from unseen speakers.

“Please present your tickets,” it said, a soft monotonous tone that made Tick feel sleepy. He clasped his ticket between his thumb and forefinger, holding it up into the air; the others did the same.

“Cleared. State your desired time of departure.”

“As soon as possible,” Sofia said in a loud voice.

“It’s not deaf,” Paul whispered, getting an elbow in the gut from Sofia in return.

“Checking departures. One moment, please.” A pause, then: “Six Forty-Four is acceptable. Please stand on the foot rest, backs against the wall.”

“Huh?” Paul asked.

“Just do it,” Sofia said, climbing on to the bench.

“Three minutes to departure.”

Tick stepped onto the padded bench, surprised at how firmly it held him. He rested his back against the soft wall; Paul and Sofia had done the same, the three of them spaced evenly apart, exchanging worried glances.

“This is weird,” Paul said.

“That about sums it up,” Tick agreed.

“It’s obviously okay. All those other people are doing it,” Sofia said. “We can’t expect every Reality to be just like ours.”

“One minute to departure.”

“What do we do—just stand here?” Paul asked.

Sofia rolled her eyes. “You can do jumping jacks if you want.”

“You’re telling me you’re not a little scared?”

“I am,” Tick said.

“Maybe a little,” Sofia said.

“Thirty seconds to departure.”

No one said a word after that; Tick counted down inside his head.

“Ten seconds.” A pause. “Five. Four. Three. Two. One. Departure initiated.”

The room began to rotate clockwise, slowly at first, but then it picked up speed.

“Oh, no,” Tick said. “I can’t do this—I’ll throw up all over you guys.”

They spun faster and faster. Tick felt a pressure on his skin, squeezing his limbs and his torso, like an invisible force pushing him against the curved wall at his back. In a matter of seconds, he’d lost track of their rotation speed, his mind and stomach disoriented, his body sinking into the padding. His thoughts whirled as fast as his body, spinning clockwise in a tight circle.

Something clicked in Tick’s mind.

He envisioned the city they’d just left, the layout, the circular road—and the solution to Chu’s riddle crystallized in his head, as clear as anything he’d ever known. In that moment, he knew they shouldn’t be on the train.

They had to stop. They had to go back!

He wanted to say something, but he couldn’t. He felt like the world was crushing him. Grunting, he tried to push his arms up into the air. It felt like he had fifty-pound dumbbells in his hands. The second he relaxed, his arms slammed back onto the wall.

Then it got worse.

A horn sounded, coming from everywhere and nowhere at once, and then the room shifted. With the spinning and the pressure, it was hard to tell which direction the room was moving, but it seemed to have dropped into a black hole, catapulting forward at a speed that was too much for Tick’s mind and body to handle.

He passed out.

Chapter

30

Forest Exit

Tick.”

He heard someone say his name, but it sounded hollow, like an echo coming down a long tunnel.

“Tick!”

There it was again. Louder this time. A sharp pain splintered across his mind, and that seemed to do the trick. Groaning, blinking through squinting eyes, he woke up.

“Dude, are you all right?”

Paul. It was Paul.

“Come on. Help him up.”

Sofia.

Tick felt hands grip him by the arms and haul him off the floor, setting him down on a soft bench. Every time he opened his eyes, all he could see were things spinning and rocking back and forth. His mind felt like a pack of termites had been set loose inside for lunch. And the nausea . . .

“I gotta throw up,” he whispered.

“Not on me, you don’t,” Paul said. “Hurry, let’s get him out of here.”

They grabbed him by the arms again. He heard a door open, felt refreshing cool air wash over him as they helped him stumble outside the portal.

“There’s a garbage can,” he heard Sofia say; they changed directions.

“Hurry,” Tick groaned, trying his best to get his feet under him. A cold line of metal pressed against his neck.

“Go for it,” Paul muttered.

Tick let it all out, then slid to the ground and leaned back against the garbage can. “Ah, that feels much better.” He opened his eyes fully and got his first good look at where they’d arrived.

The station looked much like the one they’d left earlier—maybe a little dirtier, less well-kept. Just as many people milled about, though, some leaving portals, some entering them.

“What happened?” he asked.

“You passed out,” Sofia said. “I think I might have, too, just for a few seconds. When we finally stopped, Paul and I slid down onto the bench, but you crashed straight to the floor.”

“Yeah, man,” Paul said. “You were out like a light.”

“How long were we in that thing?” Tick asked.

Sofia looked at her watch. “Only a half-hour or so.”

“Worst half-hour of my life,” Paul said.

Tick rubbed his face with both hands, then stood up, wobbling for a second before he felt his legs strengthen and solidify beneath him. “We have to go back. Now.”

“Go back?” Paul asked. “Are you crazy?”

“We need to look around,” Sofia said. “Figure out what Chu wants us to do.”

Tick shook his head, which sent another wave of nausea through his gut. “No, we got it wrong. We weren’t supposed to come here. The trains have nothing to do with the riddle.”