Around ten o’clock at night they left the motel, drove past the Old Oaks Country Club, and turned north onto a two-lane road. The research center was easy to find. Sodium security lights were mounted on the wall and a security guard sat in a booth at the entrance. Hollis kept glancing in the side mirror, but no one followed them. A mile later, he took a side road north and parked on the shoulder near a grove of apple trees. The apples had been picked weeks ago and dead leaves covered the ground.

It was very quiet in the truck. Maya realized that she’d gotten used to the music coming from the speakers; it had sustained them during the journey.

“This is going to be difficult,” Hollis said. “I’m sure there are a lot of security guards inside the research center.”

“You don’t have to go.”

“I know you’re doing this for Gabriel, but we got to save Vicki, too.” Hollis looked out the windshield at the night sky. “She’s smart and brave, and she stands up for what’s right. Any man would be lucky to be part of her life.”

“It sounds like you want to be that person.”

Hollis laughed. “If I was lucky I wouldn’t be sitting in a beat-up truck with a Harlequin. You people have way too many enemies.”

They got out of the pickup and pushed their way through a dense thicket of pin oaks and blackberry bushes. Maya was carrying her sword and the combat shotgun. Hollis took along a semiautomatic rifle and a canvas bag filled with the tools. When they came out of the trees near the north wall of the research center, they found a ventilation duct coming out of the ground. The opening was covered with a heavy steel grate.

Hollis cut off two padlocks with the bolt cutters and pried up the grate with the crowbar. He shone the flashlight in the duct, but the light beam didn’t reach beyond ten feet. Maya felt warm air touch her skin.

“According to the blueprint, the duct goes straight to the basement,” she told Hollis. “I can’t tell if there’s room enough to maneuver, so I’ll go headfirst.”

“How will I know if you’re all right?”

“Let me down at three-foot intervals. If I snap the rope twice it’s okay to let out some more line.”

Maya pulled on the rock-climbing harness while Hollis attached a carabiner and pulley to the edge of the grate. After everything was secure, the Harlequin went down the ventilation duct with a few tools held beneath her jacket. The steel duct was dark, hot, and just wide enough for one person. She felt as if she was being lowered into a cave.

After forty feet of rope was released, Maya reached a T junction where the duct went off in two different directions. Hanging upside down, she pulled out the hammer and chisel and got ready to cut through the sheet metal. When the chisel blade hit the duct, the sound echoed around her. Sweat dripped down her face as she swung the hammer again and again. Suddenly, the chisel cut through the steel and a thin sliver of light appeared. Maya cut out a hole and pried back the steel. She snapped the line twice and Hollis lowered her into an underground tunnel with a concrete floor and cinder-block walls. The tunnel was lined with water, power, and ventilation pipes. The only illumination came from a series of fluorescent fixtures placed at twenty-foot intervals.

It took ten minutes to double up the climbing rope and lower down a knapsack with the tools. Five minutes after that, Hollis was standing beside her.

“How do we get upstairs?” he asked.

“On the north corner of the building, there’s an emergency staircase. We’ve got to find the staircase without triggering the security system.”

They went down the tunnel and stopped at the first open doorway. Maya took out a small mirror and held it at an angle. On the other side of the door frame was a small white plastic box with a curved diffuser lens.

“The blueprints said that they’re using PIR motion detectors. It senses the infrared energy given off by objects and trips an alarm if it goes above a certain limit.”

“And that’s why we got the nitrogen?”

“Right.” She reached into the knapsack and pulled out the liquid nitrogen. The container looked like a thermos with a nozzle on one end. Carefully, she reached through the door frame and sprayed the motion detector. When it was covered with white frost, they continued down the tunnel.

The engineers who had built the underground area had painted sector numbers on the walls, but Maya didn’t understand their meaning. In certain areas of the tunnel, they could hear a constant mechanical hum that sounded like a steam turbine, but the machinery remained out of sight. After wandering around for ten minutes, they reached another junction in the tunnel. Two passageways led off in different directions with no signs indicating the right path. Reaching into her pocket, Maya took out the random number generator. Odd number means right, she decided, and pressed the button. Number 3531 appeared.

“Go right,” she told Hollis.

“Why?”

“No reason at all.”

“The tunnel on the left looks bigger. I say we go that way.”

They went left and spent ten minutes exploring empty storage rooms. Finally the passageway hit a dead end. When they turned back, they found the Harlequin lute that Maya had scratched on the wall with her knife.

Hollis looked annoyed. “This doesn’t mean your little number machine gave us the correct choice. Give me a break, Maya. The number doesn’t mean anything.”

“It means we go right.”

They entered the second passageway and disabled another motion detector. Suddenly Hollis stopped and pointed up. A small silver box was mounted on the ceiling. “Is that a motion detector?”

Maya shook her head and put her hand to her lips.

“Just tell me what it is.”

She grabbed his arm and they ran down the passageway. Pushing open a steel door, they entered a room the size of a football field that was filled with concrete support pillars.

“What the hell is going on?”

“That was their backup system. A sound detector. It probably feeds into a computer program called Echo. The computer filters out mechanical noises and detects the sound of a human voice.”

“So they know we’re here?”

Maya opened up the top of her sword case. “The detector could have picked up our voices twenty minutes ago. Come on, we’ve got to find the staircase.”

The basement area had only five sources of light: a single lightbulb in each of the distant corners and a fifth bulb in the middle. They left the corner of the room and walked slowly between the gray pillars to the light at the center. The concrete floor was dusty, and the air was hot and stagnant.

The lightbulbs flickered, and then died. For a few seconds they stood in complete darkness until Hollis switched on their only flashlight. He looked tense and ready to fight.

They heard a squeaking, raspy sound as if a door was being forced open. Silence. Then the door was shut with a hollow boom. The tips of Maya’s fingers were tingling. She touched Hollis’s arm-don’t move-and they both heard a quick barking noise that sounded like laughter.

Hollis pointed the flashlight between two rows of pillars and they saw something pass through the shadows. “Splicers,” he said. “They sent them down to kill us.”

Maya reached into the knapsack and found the propane blowtorch. Her hands were awkward, fumbling, as she turned the steel knob and lit the nozzle with a cigarette lighter. A blue flame came out of the nozzle with a soft roaring sound. She held it up and took a few steps forward.

Dark shapes passed between the pillars. More quick laughter. The splicers were changing position, running in a circle around them. Maya and Hollis stood with their backs to each other within the small circle of light.

“They don’t die easy,” Hollis told her. “And if you shoot them in the body, the wound heals right away.”