She passed a hand over her brow, noticing as she did so that her fingertips were trembling slightly. She tried not to think of anything beyond the lab work. She had to be finished and long gone by dawn. Her head pounded; she was dead tired; she hadn't slept since returning home two days before. But her anger and her grief gave her energy, fed her, kept her going. Pendergast needed the DNA results as soon as possible. She was grateful for the chance to be of use — any use — if it would help catch Bill's murderer.

From a lab refrigerator, she took out a strip of eight PCR tubes: tiny, bullet — shaped sealed plastic containers pre — filled with buffer solution, Taq polymerase, dNTPs, and other reagents. With exquisite care, she used a pair of sterilized tweezers to transfer minuscule samples of the biological material from her test tubes to the PCR tubes, quickly resealing each one as she did so. By the time the machine trilled its readiness, she had filled thirty — two: the maximum the PCR cycler could hold in a single run.

She slipped a few extra tubes into her pocket for later use, then went over the instructions for the third time. She opened the cycler, slotted in the reaction tubes, then closed and locked it down. Setting the controls, she gingerly pressed the start button.

It would take forty thermal cycles, each lasting three minutes, to complete the PCR reaction. Two hours. Then, she knew, she would have to submit the results to gel electrophoresis in order to identify the DNA.

The machine issued another soft chime, and a screen indicated that the first thermal cycle was in progress. Nora sat back, waiting. Only now did she realize how deathly silent it was in the lab. There wasn't even the usual sound of air moving through the circulation system. The room smelled of dust, mold, and the faint sweetness of para — dichlorobenzene from the nearby storage areas.

She glanced up at the clock: twelve twenty — five. She should have brought a book. In the silent lab, she found herself alone with her thoughts — and they were terrible thoughts.

She got up and paced across the lab, returned to the table, sat down, got up once again. She hunted through cupboards for something to read, finding only manuals. She thought of going up to her office, but there was always the danger of running into someone and having to explain why she was in the museum at such a late hour. She had no clearance to be in the PCR lab. She hadn't signed up for it, she hadn't recorded her presence in the log. Even if she had, she wasn't authorized to use the machine… Suddenly she halted, listening. She had heard a noise, or thought she had. Outside the door.

She glanced over to the little window, but there was nothing to see except the dim hallway beyond, illuminated by a lightbulb in a metal cage. The LED in the door's keypad glowed red: it was still locked.

With a groan, she clenched her fists together. It was hopeless: horrible images kept coming, unbidden, sweeping into her consciousness without warning. She squeezed her eyes closed, tightened her fists still further, trying to think of anything but that first glimpse…anything …

Her eyes popped open again. There was that noise again, and this time she identified it: a soft scraping against the lab door. Glancing up quickly, she just caught a shape moving beyond the window. She had the distinct feeling that someone had just looked in on her.

One of the night watchmen? It was possible. With a stab of anxiety, she wondered if they would report her unauthorized presence. Then she shook her head. If they'd suspected anything, they would have come in and confronted her. How would they know she wasn't supposed to be there? After all, she had her ID and was clearly a curator. It was her mind, playing tricks on her again. It had been doing that ever since… She turned her eyes away from the window. Maybe shewas going crazy.

The sound came again, and her eyes shot back toward the window. This time, she saw a dark silhouette of a head bobbing in the hallway beyond, swaying a little, backlit and indistinct. It loomed in the little window — and then, as it pressed up against the glass, the light from the lab revealed its features.

She caught her breath, blinked, and stared again.

It was Colin Fearing.

Nora jumped back with a cry. The face vanished. She felt her heart accelerate, thudding in her chest. There was no question this time.

This was no dream.

She scrambled backward, looking around wildly for a place to hide, and ducked behind a lab table, gasping for breath.

There was no sound. The lab, and the hallway beyond, were utterly silent. She thought: This is stupid. The door's locked. He can't get in. A minute passed. As she crouched there, breathing fast, a strange thing happened. The fear that had instinctively gripped her melted away. Rage began to take its place.

Slowly, she stood up. The window remained empty.

Her hand moved across the tabletop, grasped a Pyrex graduated cylinder, and lifted it from its stand. Then, with a sharp rap, she knocked it against the edge of the stand, shattering its end. More quickly now, she moved to the door, shaking fingers trying to punch in the code. On the third try she got it, threw open the door, and stepped into the hall.

From around the far bend of the hall came the sound of a door closing. "Fearing!" she cried.

She broke into a run, charging at top speed down the hall and around the corner. The hall was lined with doors, but only one was near the intersection. She seized its handle, found it unlocked, jerked it open.

She fumbled along the wall, felt the banks of light switches, and in two swipes of her hand turned them all on.

Ahead lay a room she had heard of but never seen, one of the museum's most legendary storage areas. It had once been the old power plant; now, the vast space contained the museum's collection of whale skeletons. The enormous bones and skulls, some as large as city buses, hung on chains from the ceiling; had they been set on the floor, their own weight would have caused them to deform and break. Each of the suspended skeletons was draped in plastic sheets that hung, shroud — like, almost to the floor, a seascape of draped bones. Despite the banks of fluorescent bulbs overhead, there were still too few for such a large room, and the lighting had a gauzy, almost submarine quality.

She glanced around, makeshift weapon at the ready. To the left, a few of the sheets were swaying, as if recently disturbed.

"Fearing!"

Her voice echoed weirdly in the cavernous vault. She ran toward the nearest shrouds, then slipped between them. The great skeletons cast strange shadows in the indistinct light, and the plastic sheets, dirty and stiff, formed a maze — like set of curtains that prevented her from seeing more than a few feet in any direction. She was almost gasping with mingled tension and rage.

She reached out and jerked aside a curtain of plastic. Nothing.

She stepped forward, pulled aside another, and then another. Now the plastic shrouds that surrounded her were swaying crazily, as if the giant skeletons within had come to restless life.

"Bastard! Show yourself!"

A rustle — and then she saw a shadow move swiftly against the plastic. She lunged forward, slashing with the cylinder.

Nothing.

Suddenly she could take it no longer and ran forward with a cry, batting aside curtain after curtain, sweeping the broken glass tube before her in wild arcs, until she became tangled in the heavy plastic and had to struggle to free herself. The fit passing, she took a few more steps, listening. At first all she heard were her own gasps of breath. But then she made out, quite distinctly, a shuffling sound to her right. She rushed toward it, slashing and lunging, preparing to call out again.