Sarah said, "What're we doing here?"

"ELF purchased a large quantity of rockets," Kenner said.

She frowned. "Rockets?"

"Small ones. Lightweight. About two feet long. They're outdated versions of an '80s Warsaw Pact device called Hotfire. Handheld, wire-guided, solid propellant, range of about a thousand yards."

Sarah wasn't sure what all that meant. "So, these are weapons?"

"I doubt that's why they bought them."

"How many did they buy?"

"Five hundred. With launchers."

"Wow."

"Let's just say they're probably not hobbyists."

Above the doors, a banner in flaking yellow and green paint read, Camping Gear Paintball Paratrooper Jackets Compass Sleeping Bags Much, Much More!

The front door chimed as they went in.

The store was large and disorderly, filled with military stuff on racks and piled in untidy heaps on the floor. The air smelled musty, like old canvas. There were few people inside at this hour. Kenner walked directly to the kid at the cash register, flashed his wallet, and asked for Mr. Brader.

"In the back."

The kid smiled at Sarah. Kenner went to the back of the store. Sarah stayed at the front.

"So," she said. "I need a little help."

"Do my best." He grinned. He was a crew-cut kid, maybe nineteen or twenty. He had a black T-shirt that said "The Crow." His arms looked like he worked out.

"I'm trying to find a guy," Sarah said, and slid a sheet of paper toward him.

"You think any guy would be trying to find you," the kid said. He picked up the paper. It showed a photograph of the man they knew as Brewster, who had set up camp in Antarctica.

"Oh yeah," the kid said immediately. "Sure, I know him. He comes in sometimes."

"What's his name?"

"I don't know, but he's in the store now."

"Now?" She glanced around for Kenner, but he was in the back, huddled with the owner. She didn't want to call to him or do anything to cause attention.

The kid was standing on tiptoes, looking around. "Yeah, he's here. I mean, he was in here a few minutes ago. Came in to buy some timers."

"Where are your timers?"

"I'll show you." He came around the counter, and led her through the stacks of green clothing and the boxes piled seven feet high. She couldn't see over them. She could no longer see Kenner.

The kid glanced over his shoulder at her. "What are you, like a detective?"

"Sort of."

"You want to go out?"

They were moving deeper into the store when they heard the chime of the front door. She turned to look. Over stacks of flak jackets, she had a glimpse of a brown head, a white shirt with a red collar, and the door closing.

"He's leaving amp;"

She didn't think. She just turned and sprinted for the door. The bag banged against her hip. She jumped over stacked canteens, running hard.

"Hey," the kid yelled behind her. "You coming back?"

She banged through the door.

She was out on the street. Glaring hot sun and shoving crowds. She looked left and right. She didn't see the white shirt and red collar anywhere. There hadn't been time for him to cross the street. She looked around the corner, and saw him strolling casually away from her, toward Fifth Street. She followed him.

He was a man of about thirty-five, dressed in cheap golf-type clothes. His pants were rumpled. He wore dirty hiking boots. He had tinted glasses and a small, trim moustache. He looked like a guy who spent a lot of time outdoors, but not a construction guymore of a supervisor. Maybe a building contractor. Building inspector. Something like that.

She tried to notice the details, to remember them. She gained on him, then decided that was a bad idea, and dropped back. "Brewster" stopped in front of one window and looked at it intently for a few moments, then went on.

She came to the window. It was a crockery store, displaying cheap plates. She wondered, then, if he already knew he was being followed.

To trail a terrorist on a downtown street felt like something out of a movie, but it was more frightening than she anticipated. The surplus store seemed very far behind her. She didn't know where Kenner was. She wished he were here. Also, she was hardly inconspicuous; the crowd on the sidewalk was largely Hispanic, and Sarah's blond head stuck up above most people's.

She stepped off the curb, and walked along the street gutter, hanging at the edge of the crowd. That way she lost six inches of height. But still, she was uncomfortably aware that her hair was distinctively blonde. But there was nothing she could do about that.

She let Brewster get twenty yards ahead of her. She didn't want to allow more distance than that because she was afraid she'd lose him.

Brewster crossed Fifth Street, and continued on. He went another half a block, and then turned left, down an alley. Sarah got to the alley entrance, and paused. There were garbage bags stacked at intervals. She could smell the rotten odor from where she was. A big delivery truck blocked the far end of the alley.

And no Brewster.

He had vanished.

It wasn't possible, unless he had walked through one of the back doors that opened onto the alley. There were doors every twenty feet or so, many of them recessed into the brick wall.

She bit her lip. She didn't like the idea that she couldn't see him. But there were delivery men down at the truck amp;.

She started down the alley.

She looked at each door as she passed it. Some were boarded shut, some were locked. A few had grimy signs giving the name of the firm, and saying USE FRONT ENTRANCE OR PRESS BELL FOR SERVICE.

No Brewster.

She had gotten halfway down the alley when something made her look back. She was just in time to see Brewster step out of a doorway and head back to the street, moving quickly away from her.

She ran.

As she passed the doorway, she saw an elderly woman standing in the door. The sign on the door said, Munro Silk and Fabrics.

"Who is he?" she shouted.

The old woman shrugged, shaking her head. "Wrong door. They all do" She said something more, but by then Sarah couldn't hear.

She was back on the sidewalk, still running. Heading toward Fourth. She could see Brewster half a block ahead. He was walking quickly, almost a jog.

He crossed Fourth. A pickup truck pulled over to the side, a few yards ahead. It was battered blue, with Arizona license plates. Brewster jumped in the passenger side, and the truck roared off.

Sarah was scribbling down the license plate when Kenner's car screeched to a stop alongside her. "Get in."

She did, and he accelerated forward.

"Where were you?" she said.

"Getting the car. I saw you leave. Did you film him?"

She had forgotten all about the bag on her shoulder. "Yes, I think so."

"Good. I got a name for this guy, from the store owner."

"Yes?"

"But it's probably an alias. David Poulson. And a shipping address."

"For the rockets?"

"No, for the launch stands."

"Where?"

Kenner said, "Flagstaff, Arizona."

Ahead, they saw the blue pickup.

They followed the pickup down Second, past the Los Angeles Times building, past the criminal courts, and then onto the freeway. Kenner was skilled; he managed to stay well back, but always kept the truck in sight.

"You've done this before," Sarah said.

"Not really."

"What is that little card you show everybody?"

Kenner pulled out his wallet, and handed it to her. There was a silver badge, looking roughly like a police badge, except it said "NSIA" on it. And there was an official license for "National Security Intelligence Agency," with his photograph.

"I've never heard of the National Security Intelligence Agency."

Kenner nodded, took the wallet back.

"What does it do?"

"Stays below the radar," Kenner said. "Have you heard from Evans?"

"You don't want to tell me?"

"Nothing to tell," Kenner said. "Domestic terrorism makes domestic agencies uncomfortable. They're either too harsh or too lenient. Everyone in NSIA is specially trained. Now, call Sanjong and read him the license plate on that pickup, see if he can trace it."

"So you do domestic terrorism?"

"Sometimes."

Ahead, the pickup truck moved onto the Interstate 5 freeway, heading east, past the clustered yellowing buildings of County General Hospital.

"Where are they going?" she said.

"I don't know," he said. "But this is the road to Arizona."

She picked up the phone and called Sanjong.

Sanjong wrote down the license, and called back in less than five minutes. "It's registered to the Lazy-Bar Ranch, outside Sedona," he told Kenner. "It's apparently a guest ranch and spa. The truck hasn't been reported stolen."

"Okay. Who owns the ranch?"

"It's a holding company: Great Western Environmental Associates. They own a string of guest ranches in Arizona and New Mexico."

"Who owns the holding company?"

"I'm checking on that, but it'll take some time."

Sanjong hung up.

Ahead, the pickup truck moved into the right lane, and turned on its blinker.

"It's pulling off the road," Kenner said.

They followed the truck through an area of seedy industrial parks. Sometimes the signs said sheet works or machine tooling, but most of the buildings were blocky and unrevealing. The air was hazy, almost a light fog.

After two miles, the truck turned right again, just past a sign that said ltsi corp. And beneath that, a small picture of an airport, with an arrow.

"It must be a private airfield," Kenner said.

"What's LTSI?" she said.

He shook his head. "I don't know."

Farther down the road, they could see the little airfield, with several small prop planes, Cessnas and Pipers, parked to one side. The truck drove up and parked alongside a twin-engine plane.

"Twin Otter," Kenner said.

"Is that significant?"

"Short takeoff, large payload. It's a workhorse aircraft. Used for fire-fighting, all sorts of things."

Brewster got out of the truck, and walked to the cockpit of the plane. He spoke briefly to the pilot. Then he got back in the truck, and drove a hundred yards down the road, pulling up in front of a huge rectangular shed of corrugated steel. There were two other trucks parked alongside it. The sign on the shed said ltsi, in big blue letters.

Brewster got out of the truck, and came around the back as the driver of the truck got out.

"Son of a bitch," Sarah said.

The driver was the man they knew as Bolden. He was now wearing jeans, a baseball cap, and sunglasses, but there was no doubt about his identity.

"Easy," Kenner said.

They watched as Brewster and Bolden walked into the shed through a narrow door. The door closed behind them with a metallic clang.

Kenner turned to Sarah. "You stay here."

He got out of the car, walked quickly to the shed, and went inside.

She sat in the passenger seat, shading her eyes against the sun, and waited. The minutes dragged. She squinted at the sign on the side of the shed, because she could detect small white lettering beneath the large ltsi initials. But she was too far away to make out what it said.

She thought of calling Sanjong, but didn't. She worried about what would happen if Brewster and Bolden came out, but Kenner remained inside. She would have to follow them alone. She couldn't let them get away amp;.

That thought led her to slide over into the driver's seat. She rested her hands on the wheel. She looked at her watch. Surely nine or ten minutes had already passed. She scanned the shed for any sign of activity, but the building was clearly made to be as unobtrusive and as unrevealing as possible.

She looked at her watch again.

She began to feel like a coward, just sitting there. All her life, she had confronted the things that frightened her. That was why she had learned to ski black diamond ice, to rock climb (even though she was too tall), to scuba dive wrecks.

Now, she was just sitting in a hot car, waiting as the minutes ticked by.

The hell with it, she thought. And she got out of the car.

At the door to the shed, there were two small signs. One said ltsi lightning test systems international. The second said warning: do not enter test bed during discharge intervals.

Whatever that meant.

Sarah opened the door cautiously. There was a reception area, but it was deserted. On a plain wooden desk was a handwritten sign and a buzzer. PRESS BUZZER FOR ASSISTANCE.

She ignored the buzzer, and opened the inner door, which was ominously marked:

NO TRESPASSING

HIGH VOLTAGE DISCHARGE

AUTHORIZED PERSONNEL ONLY

She went through the door and came into an open, dimly lit industrial spacepipes on the ceiling, a catwalk, rubber-tile floor underfoot. It was all quite dark except for a two-story glass-walled chamber in the center, which was brightly lit. It was a fairly large space, roughly the size of her living room. Inside the chamber she saw what looked like an airplane jet engine, mounted on a small section of wing. At the side of the room was a large metal plate, set against the wall. And outside the room was a control panel. A man was sitting in front of the panel. Brewster and Bolden were nowhere to be seen.

Inside the room, a recessed monitor screen flashed clear area now. A computer voice said, "Please clear the test area. Testing begins in amp;thirty seconds." Sarah heard a slowly building whine, and the chugging of a pump. But nothing was happening that she could see.

Curious, she moved forward.

"Ssst!"

She looked around, but could not see where the sound was coming from.

"Ssst!"

She looked up. Kenner was above her, on the catwalk. He gestured for her to join him, pointing to a set of stairs at the corner of the room.

The computer voice said, "Testing begins in amp;twenty seconds."

She climbed the stairs and crouched beside Kenner. The whine had now built to a shriek, and the chugging was rapid, almost a continuous sound. Kenner pointed to the jet engine, and whispered, "They're testing airplane parts." He explained quickly that airplanes were frequently struck by lightning, and all their components had to be lightning proof. He said something else, too, but she couldn't really hear him over the increasing noise.