"We'll start getting calls now," she said. "The cat is out of the bag."

There were a dozen security guards standing outside Hangar 5, where the Transpacific jet was being inspected. But this was standard procedure whenever a RAMS team from Recovery and Maintenance Services entered the plant. RAMS teams circled the globe, troubleshooting stranded aircraft; they were FAA-licensed to repair them in the field. But since members were chosen for expertise rather than seniority, they were non-union; and there was often friction when they came into the factory.

Within the hangar, the Transpacific widebody stood in the glare of halogen lights, nearly hidden behind a gridwork of roll-up scaffolding. Technicians swarmed over every part of the plane. Casey saw Kenny Burne working the engines, cursing his powerplant crew. They had deployed the two thrust reverser sleeves that flared out from the nacelle, and were doing fluorescent and conductivity tests on the curved metal cowls.

Ron Smith and the electrical team were standing on a raised platform beneath the midships belly. Higher up, she saw Van Trung through the cockpit windows, his crew testing the avionics.

And Doherty was out on the wing, leading the structure team. His group had used a crane to remove an eight-foot aluminum section, one of the inboard slats.

"Big bones," Casey said to Richman. "They inspect the biggest components first."

"It looks like they're tearing it apart," Richman said.

A voice behind them. "It's called destroying the evidence!"

Casey turned. Ted Rawley, one of the flight test pilots, sauntered up. He was wearing cowboy boots, a western shirt, dark sunglasses. Like most of the test pilots, Teddy cultivated an air of dangerous glamour.

"This is our chief test pilot," Casey said. 'Teddy Rawley. They call him Rack 'em Rawley."

"Hey," Teddy protested. "I haven't drilled a hole yet. Anyway, it's better than Casey and the Seven Dwarfs."

"Is that what they call her?" Richman said, suddenly interested.

"Yeah. Casey and her dwarfs." Rawley gestured vaguely to the engineers. "The little fellas. Heigh-ho, heigh-ho." He turned away from the plane, punched Casey on the shoulder. "So: How you doing, kid? I called you the other day."

"I know," she said. "I've been busy."

"I'll bet you have," Teddy said. "I bet Marder's got the screws on everybody. So: What've the engineers found? Wait a minute, let me guess-they found absolutely nothing, right? Their beautiful plane is perfect. So: Must be pilot error, am I right?"

Casey said nothing. Richman looked uncomfortable.

"Hey," Teddy said. "Don't be shy. I've heard it all before. Let's face it, the engineers are all card-carrying members of the Screw the Pilots Club. That's why they design planes to be practically automatic. They just hate the idea that somebody might actually fly them. It's so untidy, to have a warm body in the seat. Makes 'em crazy. And of course, if anything bad happens, it must be the pilot. Gotta be the pilot. Am I right?"

"Come on, Teddy," she said. "You know the statistics. The overwhelming majority of accidents are caused by-"

It was at that point that Doug Doherty, crouched on the wing above them, leaned over and said dolefully, "Casey, bad news. You'll want to see this."

"What is it?"

"I'm pretty sure I know what went wrong on Flight 545."

She climbed the scaffolding and walked out on the wing. Doherty was crouched over the leading edge. The slats were now removed, exposing the innards of the wing structure.

She got down on her hands and knees next to him, and looked.

The space for the slats was marked by a series of drive tracks-little rails, spaced three feet apart, that the slats slid out on, driven by hydraulic pistons. At the forward end of the rail was a rocker pin, which allowed the slats to tilt downward. At the back of the compartment she saw the folding pistons which drove the slats along the tracks. With the slats removed, the pistons were just metal arms poking out into space. As always, whenever she saw the innards of an aircraft, she had a sense of enormous complexity.

"What is it?" she said.

"Here," Doug said.

He bent over one of the protruding arms, pointing to a tiny metal flange at the back, curved into a hook. The part was not much larger than her thumb.

"Yes?"

Doherty reached down, pushed the flange back with his hand. It flicked forward again. "That's the locking pin for the slats," he said. "It's spring-loaded, actuated by a solenoid back inside. When the slats retract, the pin snaps over, holds them in place."

"Yes?"

"Look at it," he said, shaking his head. "It's bent"

She frowned. If it was bent, she couldn't see it. It looked straight to her eye. "Doug…"

"No. Look." He set a metal ruler against the pin, showing her that the metal was bent a few millimeters to the left. "And that's not all," he said. "Look at the action surface of the hinge. It's been worn. See it?"

He handed her a magnifying glass. Thirty feet above the ground, she leaned over the leading edge and peered at the part. There was wear, all right. She saw a ragged surface on the locking hook. But you would expect a certain amount of wear, where the metal of the latch engaged the slats. "Doug, do you really think this is significant?"

"Oh yes," he said, in a funereal tone. "You got maybe two, three millimeters of wear here."

"How many pins hold the slat?"

"Just one," he said.

"And if this one is bad?"

"The slats could pop loose in flight. They wouldn't necessarily fully extend. They wouldn't have to. Remember, these are low-speed control surfaces. At cruise speed the effect magnifies: a slight extension would change the aerodynamics."

Casey frowned, squinting at the little part through the magnifying glass. "But why would the lock suddenly open, two-thirds of the way through the flight?"

He was shaking his head. "Look at the other pins," Doherty said, pointing down the wing. "There's no wear on the action surface."

"Maybe the others were changed out, and this one wasn't?"

"No," he said. "I think the others are original. This one was changed. Look at the next pin down. See the parts stamp at the base?'

She saw a tiny embossed figure, an H in a triangle, with a sequence of numbers. All parts manufacturers stamped their parts with these symbols. "Yeah…"

"Now look at this pin. See the difference? On this part, the triangle is upside down. This is a counterfeit part, Casey."

For aircraft manufacturers, counterfeiting was the single biggest problem they faced as they approached the twenty-first century. Media attention focused mostly on counterfeit consumer items, like watches, CDs, and computer software. But there was a booming business in all sorts of manufactured items, including auto parts and airplane parts. Here the problem of counterfeiting took a new and ominous turn. Unlike a phony Cartier watch, a phony airplane part could kill you.

"Okay," she said. "I'll check the maintenance records, find out where it came from."

The FAA required commercial carriers to keep extraordinarily detailed maintenance records. Every time a part was changed out, it was noted in a maintenance log. In addition, the manufacturers, though not required to, maintained an exhaustive ship's record of every part originally on the plane, and who had manufactured it. All this paperwork meant that every one of the aircraft's one million parts could be traced back to its origin. If a part was swapped out from one plane to another, that was known. If a part was taken off and repaired, that was known. Each part on a plane had a history of its own. Given enough time, they could find out exactly where this part had come from, who had installed it, and when.