More than a little irritated to find that the dead could he as bothersome as the living, I picked up the Ziploc containing the letter and carried it to the front room. The note was brief and handwritten.

David,

We must meet again. I finally confronted Godin with my suspicions. His reaction astounded me. I don't want to commit anything to paper, but I know I'm right. Lu Li and I are driving to the blue place on Saturday night. Please join us. It's close quarters, but discreet. It may be time for you to contact your late brother's friend again, though I wonder if even he can do anything at this point. Things like this have a momentum greater than individuals. Greater even than humanity, I fear. If anything should happen to me, don't forget that little gold item I asked you to hold for me one day. Desperate times, mate. I'll see you Saturday.

There was no signature, but below the note was a hand-drawn cartoon of a rabbit's head and the face of a clock. The White Rabbit, an affectionate nickname given Fielding by his Cambridge physics students. Fielding always carried a gold pocket watch, and that was the "little gold item" that he had asked me to hold for him one day.

We were passing each other in the hallway when he pressed the watch and chain into my hand. "Mind keep¬ing that for an hour, old man?" he'd murmured. "Lovely." Then he was gone. An hour later he stopped by my office to pick it up, saying he hadn't wanted to take the watch into the MRI lab with him, where it could have been smashed against the MRI unit by the machine's enormous magnetic fields. But Fielding visited the MRI lab all the time, and he'd never given me his pocket watch before. And he never did again. It must have been in his pocket when he died. So what the hell was he up to that day?

I read the note again. Lu Li and I are driving to the blue place on Saturday night. Lu Li was Fielding's new Chinese wife. The "blue place" had to be code for a beach cabin at Nags Head, on North Carolina 's Outer Banks. Three months ago, when Fielding asked for a recommendation for his honeymoon, I'd suggested the Nags Head cabin, which was only a few hours away. Fielding and his wife had loved the place, and the Englishman had apparently thought of it when he wanted a secure location to discuss his fears.

My hands were shaking. The man who had written this note was now as cold as the morgue table he was living on, if indeed he was lying in a morgue. No one had been able-or willing-to tell me where my friend's body would be taken. And now the white powder. Would Fielding have put powder in the envelope and neglected to mention it in his letter? If he didn't, who did? Who but the person who had murdered him?

I laid the letter on the sofa, stripped off the surgical gloves, and rewound the videotape to the point at which I'd walked out of the frame. I had decided to make this tape because I feared I might be killed before I could tell the president what I knew. Fielding's letter had changed nothing. Yet as I stared into the lens, my mind wandered. I was way ahead of Fielding on calling my "late brother's friend." The moment I'd seen Fielding's corpse on the floor of his office, I knew I had to call the presi¬dent. But the president was in China. Still, as soon as I got clear of the Trinity lab, I'd called the White House from a pay phone in a Shoney's restaurant, a "safe" phone Fielding had told me about. It couldn't be seen by surveillance teams in cars, and the restaurant's interior geometry made it difficult for a parabolic microphone to eavesdrop from a distance.

When I said "Project Trinity," the White House oper¬ator put me through to a man who gruffly asked me to state my business. I asked to speak to Ewan McCaskell, the president's chief of staff, whom I'd met during my visit to the Oval Office. McCaskell was in China with the president. I asked that the president be informed that David Tennant needed to speak to him urgently about Project Trinity, and that no one else involved with Trinity should be informed. The man said my message would be passed on and hung up.

Thirteen hours separated North Carolina and Beijing. That made it tomorrow in China. Daylight. Yet four hours had passed since my call, and I'd heard nothing. Would my message be relayed to China, given the critical nature of the summit? There was no way to know. I did know that if someone at Trinity heard about my call first, I might wind up as dead as Fielding before I talked to the president.

I hit START on the remote control and spoke again to the camera.

"In the past six months I've gone from feeling like part of a noble scientific effort to questioning whether I'm even living in the United States. I've watched Nobel laureates give up all principles in a search for-"

I went still. Something had passed by one of my front windows. A face. Very close, peering inside. I'd seen it through the sheer curtains, but I was sure. A face, framed by shoulder-length hair. I had a sense of a woman's features, but…

I started to get up, then sat back down. My teeth were vibrating with an electric pain like aluminum foil crushed between dental fillings. My eyelids felt too heavy to hold open. Not now, I thought, shoving my hand into my pocket for my prescription bottle. Jesus, not now. For six months, every member of Trinity's inner circle had suf¬fered frightening neurological symptoms. No one's symp¬toms were the same. My affliction was narcolepsy. Narcolepsy and dreams. At home, I usually gave in to the trancelike sleep. But when I needed to fight off a spell-at Trinity, or driving my car-only amphetamines could stop the overwhelming waves.

I pulled out my prescription bottle and shook it. Empty. I'd swallowed my last pill yesterday. I got my speed from Ravi Nara, Trinity's neurologist, but Nara and I were no longer speaking. I tried to rise, thinking I'd call a pharmacy and prescribe my own, but that was ridiculous. I couldn't even stand. A leaden heaviness had settled into my limbs. My face felt hot, and my eyelids began to fall.

The prowler was at the window again. In my mind, I raised my gun and aimed it, but then I saw the weapon lying in my lap. Not even survival instinct could clear the fog filling my brain. I looked back at the window. The face was gone. A woman's face. I was sure of it. Would they use a woman to kill me? Of course. They were pragmatists. They used what worked.

Something scratched at my doorknob. Through the thickening haze I fought to aim my gun at the door. Something slammed against the wood. I got my finger on the trigger, but as my swimming brain transmitted the instruction to depress it, sleep annihilated consciousness like fingers snuffing a candle flame.

Andrew Fielding sat alone at his desk, furiously smoking a cigarette. His hands were shaking from a confrontation with Godin. It had happened the previous day, but Fielding had the habit of replaying such scenes in his mind, agonizing over how ineffectually he had stated his case, murmuring retorts he should have made at the time but had not.

The argument had been the result of weeks of frustra¬tion. Fielding didn't like arguments, not ones outside the realm of physics, anyway. He'd put off the meeting until the last possible moment. He pottered around his office, pondering one of the central riddles of quantum physics: how two particles fired simultaneously from the same source could arrive at the same destination at the same instant, even though one had to travel ten times as far as the other. It was like two 747s flying from New York to Los Angeles-one flying direct and the other having to fly south to Miami before turning west to Los Angeles- yet both touching down at LAX at the same moment. The 747 on the direct route flew at the speed of light, yet the plane that had to detour over Miami still reached L.A. at the same instant. Which meant that the second plane had flown faster than the speed of light. Which meant that Einstein's theory of Special Relativity was flawed. Possibly. Fielding spent a great deal of time thinking about this problem.