Now the camera panned back down to the kid, who was tugging her foot into her mouth, slobbering over her toes.

'Taste good?" the man said, laughing. "Is that breakfast for you, Sarah? Not waiting for the stewardess on this flight?"

Abruptly, the wife jerked her head around, looking past the camera. "What was that?" she said in a worried tone.

'Take it easy, Em," the man answered, still laughing.

Casey said, "Stop the tape."

Harmon hit a key. The image froze on the wife's anxious expression.

"Run it back five seconds," Casey said.

The white frame counter appeared at the bottom of the screen. The tape ran backward, streaking jags again.

"Okay," Casey said. "Now turn the sound up."

The baby sucked its toes, the slobbering so loud, it almost sounded like a waterfall. The hum inside the cabin became a steady roar. 'Taste good?" the man said, laughing very loudly, his voice distorted. "Is that breakfast for you, Sarah? Not waiting for the stewardess on this flight?"

Casey tried to listen between the man's sentences. To hear the sounds of the cabin, the soft murmur of other voices, rustle of fabric moving, the intermittent clink of knives and forks from the forward galley…

And now something else.

Another sound?

The wife's head jerked around. "What was that?"

"Damn," Casey said.

She couldn't be sure. The roar of ambient cabin sound drowned out anything else. She leaned forward, straining to hear.

The man's voice broke in, his laugh booming: 'Take it easy, Em."

The baby giggled again, a sharp earsplitting noise.

Casey was shaking her head in frustration. Was there a low-pitched rumble or not? Perhaps they should go back, and try to hear it again. She said, "Can you put this through an audio filter?'

The husband said, "We're almost home, honey."

"Oh my God," Harmon said, staring at the tape.

On the monitor, everything seemed to be crazy angles. The baby slid forward on the mother's lap; she grabbed at the kid, clutched it to her chest. The camera was shaking and twisting. Passengers in the background were yelling, grabbing the armrests, as the plane went into a steep descent.

Then the camera twisted again, and everybody seemed to sink in the seats, the mother slumping down under the G-force, her cheeks sagging, shoulders falling, baby crying. Then the man shouted, "What the hell?" and the wife rose into the air, restrained only by the seat belt.

Then the camera flew up in the air, and there was an abrupt, crunching sound, after which the image began to spiral rapidly. When the image became steady again, it showed something white, with lines. Before she could register what it was, the camera moved and she saw an armrest from below, fingers gripping the pad. The camera had fallen in the aisle and was shooting straight up. The screams continued.

"My God," Harmon said again.

The video image began to slide, gaining speed, moving past seat after seat. But it was going aft, she realized: the plane must be climbing again. Before she could get her bearings, the camera lifted into the air.

Weightless, she thought. The plane must have reached the end of the climb, and now it was nosing over again, for a moment of weightlessness before-

The image crashed down, twisting and tumbling rapidly. There was a thunkl and she glimpsed a blurred gaping mouth, teeth. Then it was moving again, and apparently landed on a seat. A large shoe swung toward the lens, kicked it.

The image spun rapidly, settled again. It was back in the aisle, facing the rear of the plane. The briefly steady image was horrifying: arms and legs stuck out into the aisle from the rows of seats. People were screaming, clutching anything they could. The camera immediately began to slide again, this time forward.

The plane was in a dive.

The camera slid faster and faster, banging into a midships bulkhead, spinning so it was now facing forward. It raced _: toward a body lying in the aisle. An elderly Chinese woman looked up in time for the camera to strike her in the forehead, and then the camera flew into the air, tumbling crazily, and came down again.

There was a close view of something shiny, like a belt buckle, and then it was sliding forward once more, into the forward compartment, still going, banging into a woman's shoe in the aisle, twisting, racing forward.

It went into the forward galley, where it lodged for a moment. A wine bottle rolled across the floor, banged into it, and the camera spun several times, then began to fall end over end, the image flipping as the camera went all the way past the forward galley to the cockpit.

The cockpit door was open; she had a brief glimpse of sky through the flight deck windows, blue shoulders and a cap, and then with a crash the camera came to rest, giving a steady view of a uniform gray field. After a moment, she realized the camera had at this point lodged beneath the cockpit door, right where Casey had found it, and it was taping the carpet There was nothing more to see, just the gray blur of carpet, but she could hear the alarms in the cockpit, the electronic warnings, and the voice reminders coming one after another, "Airspeed… Airspeed," and "Stall… Stall." More electronic warnings, excited voices shouting in Chinese.

"Stop the tape," she said.

Harmon stopped it.

"Jesus Christ," he said.

She ran through the tape once more, and then did it in slow motion. But even in slow motion, she realized, much of the movement was an indistinguishable blur. She kept saying, "I can't see, I can't see what's happening."

Harmon, who had by now become accustomed to the sequence, said, "I can do an enhanced frame analysis for you."

"What's that?'

"I can use the computers to go in and interpolate frames where the movement is too fast."

"Interpolate?"

"The computer looks at the first frame, and the frame following, and generates an intermediate frame between the two. It's a point-mapping decision, basically. But it will slow down-"

"No," she said. "I don't want anything added by the computers. What else can you do?"

"I can double or triple the frames. In fast segments, it would give you a little jerkiness, but at least you'd be able to see. Here, look." He went to one segment, where the camera was tumbling through the air, then slowed it down. "Now here, all these frames are just a blur-it's camera movement, not subject movement-but here. See this one frame here? You get a readable image."

It showed a view looking back down the aircraft. Passengers falling over the seats, their arms and legs streaks from swift movement.

"So that's a usable frame," Harmon said. She saw what he was driving at. Even in rapid movement the camera was steady enough to create a useful image, every dozen frames or so.

"Okay," she said, "do it."

"We can do more," he said. "We can send it out, and-"

She shook her head. "Under no circumstances does this tape leave this building," she said.

"Okay."

"I need you to run me two copies of this videotape," she said. "And make sure you run it all the way to the end."