This time Capitaine Lavoisier acquiesced, giving Moot permission to act as Theo's bodyguard until the end of the day. Moot took his usual unmarked car and drove to CERN. He suspected CERN was like most places: the transponder signal from a staff member's car would let it pass automatically through the gate, but Moot had to stop and show his badge to the guard computer before the barrier was lifted. He also asked the computer for direction; the CERN campus consisted of dozens of mostly empty buildings. It took him about five minutes to find the LHC control center. He let his car settle to the asphalt and hurried inside.

An attractive middle-aged woman with freckles was coming down a corridor lined with a series of mosaics. Moot showed her his badge. "I'm looking for Theo Procopides," he said.

The woman nodded. "He was here earlier today; let's see if we can find him."

The woman led the way deeper into the building; she tried a couple of rooms, but Theo was in neither of them. "Let's try my husband's office," she said. "He and Theo work together." They went down another corridor, and entered an office. "Jake, this man's a police officer. He's looking for Theo."

"He's down in the tunnel," said Jake. "That damned cryostat cluster in octant three."

"He may be in trouble," said Moot. "Can you take me to him?"

"In trouble?"

"In his vision, he is shot dead today — and I've got reason to believe it was down in the tunnel."

"My God," said Jake. "Um, sure, sure — I can take you to him, and — damn! God damn it, but he must have taken the monorail."

"The monorail?"

"There's a monorail that runs around the ring. But he'll have taken it ten kilometers from here."

"There's only one train?"

"We used to have three more, but we sold them off years ago. We've only got one left."

"You could fly over to the far access station," said the woman. "There's no road, but you could easily fly over the farmers' fields."

"Right — right!" said Jake. He smiled at his wife. "Beautiful and brilliant!" He turned to Moot. "Come on!"

Jake and Moot hurried down the corridors, through the lobby, and out into the parking lot. "We'll take my car," said Moot. They got in, Moot hit the start button, and the car rose off the ground. He followed Jake's instructions for getting out of the campus. Then Jake pointed across an open farmer's field.

The car flew.

Theo looked at the cryostat cluster's housing. No wonder Jiggs had been having trouble fixing it: he'd been going in through the wrong access port. The panel he'd been working behind was still open but the potentiometers Jiggs used to fiddle with were hidden behind another panel.

Theo tried to open the access door that should have let him get at the right controls, but it wouldn't budge. After years of disuse in the dark, damp tunnel, the door had apparently corroded shut. Theo rummaged in his toolkit looking for something he could use to pry it open, but all he had were some screwdrivers that proved inadequate to the task. What he really needed was a crowbar or something similar. He swore in Greek. He could take the monorail back to the campus and get the appropriate tool, but that seemed like such a waste of time. Surely there was something down here in the tunnel that he could use. He looked back the way he'd come; he hadn't noted anything like what he needed during the last few hundred meters of his trip on the monorail but, of course, he wasn't really looking. Still, it seemed to make more sense to continue on clockwise around the tunnel, at least a short distance, and see if he could find something that would do the trick.

The far access station was an old concrete bunker in the middle of a farmer's colza field. Moot's car settled down on the small driveway — there was an access road leading out in the opposite direction — and he shut off its engine. He and Jake got out.

It was noon, and, since this was October, the sun didn't get very high in the sky. But at least the bees, which were a nuisance in summer, were gone. Up the mountainsides there were mostly conifers, of course, but down here there were lots of deciduous trees. The leaves on many of them had already changed color.

"Come on," said Jake.

Moot hesitated. "There's no chance of radiation, is there?"

"Not while the collider is turned off. It's perfectly safe."

As they came toward the blockhouse, a hedgehog scurried by, quickly hiding itself in the ninety-centimeter colza shoots. Jake stopped short at the door. It was an old-fashioned hinged door, with a deadbolt lock. But the door had been pried open; a crowbar lay in the grass next to the blockhouse.

Moot moved to the door. "No corrosion," he said, indicating the metal exposed where the lock had been broken. "This was done recently." He used the toe of his fancy shoes to nudge the crowbar slightly. "The grass underneath is still green; this must have happened today or yesterday." He looked at Jake. "Anything valuable kept down there?"

"Valuable yes," said Jake. "But salable? Not unless you know of a black-market for obsolete high-energy physics equipment."

"You say this collider hasn't been used recently?"

''Not for a few years."

"Might be squatters," said Moot. "Could someone live down there?"

"I — I suppose. It'd be cold and dark, but it is watertight." Moot had a pouch at his hip; he pulled it open and removed a small electronic device, which he waved over the crowbar. "Lots of fingerprints," he said. Jake looked over; he could see the fingerprints fluorescing on the device's display screen. Moot pushed some buttons on his device. After about thirty seconds, some text scrolled across the screen. "No matches on file. Whoever did this has never been arrested anywhere in Switzerland or the E.U." A pause. "How far away is Procopides?"

Jake pointed. "About five kilometers that way. But there should be a couple of hovercarts parked here; we'll take one of those."

"Does he have a cellular? Can we phone him?"

"He's buried beneath a hundred meters of soil," said Jake. "Cell phones don't work."

They hurried into the blockhouse.

Theo had walked a couple of hundred meters down the tunnel without finding anything that would help him pry open the access door on the cryostat cluster. He glanced back; the cluster itself had disappeared around the gentle curve of the ring. He was about to give up in defeat and head back to the monorail when something caught his eye up ahead. It was somebody else, working next to one of the sextupole magnets. The person wasn't wearing a hardhat — a violation of regulations, that. Theo thought about calling out to him, but the acoustics were so bad in the tunnel he'd long ago learned not to bother trying to shout over any distance. Well, it didn't matter who it was, as long as he had a more complete toolkit than the one Theo had brought.

It took Theo another minute to get close to the man. He was working next to one of the air pumps; the racket it made must have masked the sound of Theo approaching. Sitting on the tunnel floor was a hovercart, a disk about a meter and a half in diameter with two single chairs under a canopy. Hovercarts had been developed for use on golf courses; they were much easier on the greens than old-fashioned motorized carts.

Back in the old days, there were thousands of CERN employees whom Theo didn't know on sight, but now, with just a few hundred, he was surprised to see somebody he didn't recognize.

"Hey, there," said Theo.

The man — a thin white fellow in his fifties with white hair and dark gray eyes — swung around, clearly startled. He did have a toolkit with him, but—

He'd opened a large access plate on the side of an air pump and had just finished inserting a device in there—