“Why would he want to do that?”

He took a moment to think about it. “Because he can, I suppose.”

“I want to talk to you about Ollie.”

“Yes?”

“He came in the restaurant at the Standard while I was meeting with Odile and Alberto. Bought a pack of cigarettes.”

“Yes?”

“Was he checking me out? For you?”

“Of course. What else do you think he would have been doing?”

“Just checking,” she said. “I mean, I am. Just making sure.”

“We needed a sense of how you were getting along with them. We were still making up our minds, at that point.”

The Blue Ant “we,” she thought. “More centrally, then, where’s Bobby?”

“Up there,” he said. “Somewhere.”

“I thought you could keep track of him.”

“Of the truck. The truck’s in the yard of a leasing firm, in a satellite city called Burnaby. Bobby and his equipment were off-loaded beside a warehouse, just north of the border, early this morning. I’ve had Oliver up all night, on that. He went down to the GPS coordinates where they stopped.”

“And?”

“Nothing, of course. We assume they switched trucks. How are things with Odile?”

“She’s gone out for a walk. When she gets back, I’ll try to work out what potential connections she might have here, to Bobby. I stayed away from that, on the flight up. Seemed too soon.”

“Good,” he said. “If you need me, use the ring-back for this call.”

She watched the scrambler do its little LED-dance as the encrypted connection was broken.

T hey took the black plastic Pelican case on in Montana. It wasn’t another fueling stop, though Tito imagined they were due for one of those soon. The pilot landed on a deserted stretch of rural highway, at dawn. Tito saw a battered old station wagon pulling up beside them, two men standing on its roof, but then Garreth told him to stay away from the windows. “They don’t want to see anyone they don’t know.”

Garreth opened the cabin door and a black case was handed in. It seemed to be very heavy. Garreth didn’t try to lift it. He strained, dragging it in, while someone Tito couldn’t see, outside, pushed. It looked to Tito like a Pelican case, plastic and waterproof, the kind Alejandro had sometimes used to bury documents and supplies. Then the door was closed, he heard the station wagon’s engine, and the pilot began to taxi. As they took off, Tito imagined he could feel the additional weight.

When they’d leveled out, the old man held a yellow plastic instrument close to the black box, then showed Garreth the readout on its screen.

They landed again within an hour, at a rural strip where another avgas truck was waiting.

They drank paper cups of coffee from a thermos the avgas man had brought, while he and the pilot fueled the plane.

“That’s really the ultimate handload he’s put together, isn’t it?” said Garreth to the old man.

“He told me he used JB Weld to seal the tips,” said the old man.

“Is that all?” Garreth asked.

“When I was a boy, we fixed holes in engine blocks with JB Weld.”

“They probably weren’t quite so radioactive,” said Garreth.

T his is Sarah,” said Odile, when Hollis found her, on the crowded café patio of a municipal gallery. The Phaeton had a GPS-based guidance system, but it also had a map. She could have walked over here, she guessed, in the time it had taken her to get the car, find the place, and find parking. And Ollie had been right about it being wide. All of this in response to Odile having phoned and asked her to lunch with someone interesting.

“Hello,” said Hollis, taking the girl’s hand, “I’m Hollis Henry.”

“Sarah Ferguson.”

Hollis was pulling up a wrought-iron chair, wondering whether she’d missed her chance to have Odile put visiting the local locative artists on hold, when the French curator said, “Fer-gus-son.”

“Oh,” said Hollis.

“Sarah is Bobby’s sister.” Odile was wearing a narrow pair of black-framed sunglasses.

“Yes,” said Sarah, with what Hollis took to be a possible lack of enthusiasm. “Odile tells me you met Bobby in Los Angeles.”

“I did,” said Hollis. “I’m doing a piece on locative art for Node, and your brother seems to be a key player.”

“Node?”

“It’s new,” said Hollis. Could Bigend, or Rausch, have known that Odile knew Bobby’s sister? “I didn’t know he had a sister.” She looked at Odile. “Are you an artist, Sarah?”

“No,” said Sarah, “I work for a gallery. Not this one.”

Hollis looked up at this retrofitted bank or government building. Saw public art, the statue of a ship, mounted where a roof started.

“We must go inside, for the food,” said Odile.

Inside, an upscale cafeteria line that for some reason made Hollis feel they were in Copenhagen. The people ahead of them looked as though they could each identify a dozen classic modern chairs by the designer’s name. They chose sandwiches, salads, and drinks; Hollis used her credit card, telling Sarah lunch was on Node. When she put her wallet back in her purse, she saw the envelope with Jimmy’s five thousand dollars. She’d almost left it in the electronic safe in the room at the Mondrian.

Sarah resembled Bobby, Hollis thought, as they settled at their table, but it looked better on a girl. She had darker hair, nicely cut, and was dressed for work in a gallery that sold art to people who expected a certain seriousness of demeanor. Mixed grays and black, good shoes.

“I had no idea you knew Bobby’s sister,” Hollis said to Odile, picking up her sandwich.

“We’ve only just met,” said Sarah, picking up her fork. “We have an ex in common, it turns out.” She smiled.

“Claude,” said Odile, “in Paris. I told you, Ollis, he knew Bobby.”

“Yes, you did.”

“I phone him,” said Odile. “He gives me Sarah’s number.”

“Not the first call from a stranger I’ve had about Bobby, in the past twenty-four hours,” said Sarah, “but at least there’s the connection through Claude. And you weren’t angry.”

“Have the others been angry?” Hollis asked.

“Some of them, yes. Others simply impatient.”

“Why? If you don’t mind my asking.”

“Because he’s a fuckup,” said Sarah.

“Artists in L.A.,” said Odile. “They try to find Bobby. His geohacks are down. Their art is gone. E-mail bounces.”

“I’ve had half a dozen calls. Someone down there must’ve known he has a sister here, and I’m in the book.”

“I know one of the artists who works with him,” Hollis said. “He was quite upset.”

“Who?”

“Alberto Corrales.”

“Did he cry?”

“No.”

“He cried on the phone,” said Sarah, spearing a slice of avocado. “Kept saying he’d lost his river.”

“But you don’t know where your brother is?”

“He’s here,” said Sarah. “My friend Alice saw him on Commercial Drive, this morning. She’s known him since high school. She called me. As a matter of fact, she called me about twenty minutes before you did,” she said to Odile. “She said hello. He couldn’t dodge her; he knew she knew it was him. Of course she had no idea people in L.A. are looking for him. He told her he was in town to talk with a label, about releasing a CD. Of course that was the first I knew of him being here.”

“Are you close?”

“Does it sound like it?”

“Sorry,” said Hollis.

“No, I’m sorry,” said Sarah. “It’s just that he’s so annoying, so irresponsible. He’s as self-centered now as he was when he was fifteen. It isn’t easy, having a monster of giftedness for a brother.”

“Gifted how?” Hollis asked.

“Mathematically. Software. You know he named himself after a piece of software developed at Lawrence Berkeley National Labs? Chombo.”

“What does Chombo…do?”

“It implements finite difference methods for the solution of partial differential equations, on block-structured, adaptively refined rectangular grids.” Sarah made a brief and probably unconscious face.