Just like that, the sympathy was gone, and she was once again leading him across the open lobby, toward the far side where two huge pillars embraced the entrance to some sort of interior hallway.

“You’d be surprised.”

They passed through the pillars, and Nick found himself peering down what appeared to be an endless corridor, lined on either side with doors to various classrooms. The corridor was lit by fluorescent tubes hanging from the ceiling, and seemed to be a place of constant motion; there were people, mainly students with backpacks, going in both directions, keeping to one side or the other, depending on direction. It was like some sort of human traffic experiment, along some endless stretch of enclosed highway.

“This is the Infinite Corridor,” Hailey said. “It runs over eight hundred feet and connects a large part of the campus. There are five levels, including one underground. It’s kind of the spine of the university, and it’s like this most of the time. Everyone going somewhere, all at once. But a few days a year, everything stops; because of a quirk in geography, the setting sun is in alignment with the corridor and the sunlight shines down the entire length of the place. It’s pretty cool. The kids call it MIThenge.”

Hailey noticed his expression.

“It’s cooler than it sounds. Or maybe it’s not. But some of us get off on that sort of thing. A happy confluence of design and accident.”

Nick tried to think of something smart to say back at her, but instead shrugged.

“You people have a lot of time on your hands.”

Hailey turned, but not down the hallway—instead she headed toward an elevator right past the entrance and hit the down button with the heel of her hand.

“Basement level?” Nick asked.

“A little deeper,” she said, as the elevator doors whiffed open.

*  *  *

Fifteen minutes later, and Nick had thoroughly lost his bearings.

Initially, he’d been correct; they’d taken the elevator to the basement level of the Infinite Corridor, and followed the long, industrial lit hallway at least a hundred yards under the MIT campus—but that was only the beginning. From there, Hailey had pointed him through an unmarked doorway to a stairwell that had led even deeper underground; when that stairwell had ended in another unmarked door, Nick had been surprised to find it locked. Hailey had pushed him aside, then produced a key from her purse. A moment later, they were in another hallway, very different from the bustling corridors above.

This hallway had smooth cement walls and an unfinished floor. There was visible ductwork running along the ceiling, and there were steam pipes riding up junctures in the walls. Even so, there were more doors along either side, some with numbers, many without.