“Before all the high-tech modern-day gadgetry, hidden corridors were a top line of defense,” April said.

They lifted the large tile from its position in the floor and slid it aside. April entered the vertical tunnel first, grabbing the sides of the ladder inside and shimmying down as speedily as she could manage. Norman followed directly after her, yanking the floor panel back into place. He could still hear the men banging on the door. And then he heard a new noise: the drill.

“Hurry!” Norman said.

“I’m almost to the ground,” April said.

“How deep is this thing? I can’t see squat.”

“Just keep going. You don’t have much farther.”

Norman was only a few yards from the bottom when light flooded the narrow shaft. At first he was happy to be able to see again, but when bullets began buzzing by his head, his mood soured. Seeing that he was only a few yards above the floor, he jumped, landing hard and rolling into the sidewall.

“Are you okay?” April asked, dragging him away from the raining gunfire.

Norman saw stars in the corner of his eyes. “I’m fine,” he said, shaking his head. “Don’t slow down because of me.”

They sprinted down a long, curved passageway for several hundred yards before it dead-ended into a blank concrete wall.

“Are you sure you got your directions right?” Norman asked, pulling a flashlight out of his utility belt and examining the wall.

April walked up and knocked on it. “The tunnel should be on the other side,” she said.

“Should be? You’ve never been down here?”

“Are you kidding? Do you see how creepy this place is?” She continued knocking on the wall until the sound under her knuckles changed. She pressed on the spot and slid back the stone facade, which revealed another glowing palm scanner. Norman took the cue and withdrew Dr. Winter’s hand, placing it on the display. The scanner flashed, and an exit was produced in the wall as a portion of it dropped into the floor.

Norman heard the echo of boots coming from the passageway behind them. “Where does this go?” he asked, not really caring as long as it was away from the two guys trying to shoot him.

“I’m not sure,” April said, poking her head into the darkness beyond. A thunderous rumble instantly answered the question. She pulled her head back just in time to watch the Metro Transit cars streak past.

“That’s not what I call smart planning,” Norman said.

“It was probably an empty tunnel a hundred years ago.”

“But not now.”

“No,” April agreed. “Not now.”

The footsteps behind them were getting louder. The two men would be upon them in seconds.