They crashed to the floor, and the case slammed shut behind them. April darted up while Norman was still dazed.

“We’ve got to hurry,” she said, descending a narrow staircase on the other side of the room, though room was a broad term for this space. It was more like a tall, triangular closet with a hard concrete floor and three bare walls. The bookcase shook beside Norman. Apparently the agents didn’t know how to get the bookcase to spin open, though they seemed determined to force the issue.

April was already twenty stairs in front of Norman when he started down. She stopped twenty steps later, where the descent diverged to the left and the right. Norman finally caught up to her. “Where are we?”

“Shhhh,” she said.

“You are such a librarian,” Norman said. He lowered his voice. “What is this place?”

“We’re under the library. This is the way to the rare-book vault.”

If Norman was shocked by the multitude of surprises—the bookcase doorways, the basement lairs, the secret vaults—he didn’t let on. This was Washington DC, after all, a city known for its duplicitous underpinnings: gallant facades covering underground tunnels and covert antechambers. Secrets lurked everywhere. Their current situation was proof.

Seeing another question forming on Norman’s lips, April put her finger up again, this time not bothering with the sound effect. Instead, she balled up her face in the angriest display she could muster, which wasn’t much, but more than enough to get the point across. Quiet!

Okay, okay, Norman mouthed. And then he turned toward a sound: there were voices coming from a doorway at the bottom of the left staircase. April began to creep toward the voices. Norman reached out a hand to stop her, but she evaded his grip.

April had almost reached the bottom of the stairs when she paused. There was something on the ground in front of her. A mouse, maybe, or a dead rat. But the proportions were all wrong. And then she realized what she was staring at: a human hand, severed at the wrist.

April caught Norman’s attention and pointed to the hand, then to the wall. Next to the open doorway at the bottom of the stairs was a digital panel, an exact copy of the one she had placed her hand on above. The hand had been used to gain access to the door. No wonder they thought they didn’t need her for this part of the job.

The growl of grinding metal filled the air. April motioned Norman closer. “They must be drilling into the vaults,” she said. “But they’re in the wrong place.”

Norman followed her back up to the top of the steps. Instead of going back to the Rosenwald Room, she headed down the other staircase, which led to another vault, the only difference being that this one was sealed shut with a steel door.