by Paul McAuley
Dick Knightly’s cowboy angels had learnt about the fundamental principles of the Many Worlds theory during their training. Their physics instructor, Fred Lehman, introduced the concept with Schrödinger’s ‘ridiculous case’, a thought experiment designed to challenge the assertion that measurement forced a quantum system to adopt a specific state, and any observer making measurements could not be isolated from the system he observed. In Schrödinger’s thought experiment, a cat was placed in a box equipped with a flask of cyanide gas, a mechanism that would break the flask if a detector was triggered by the random decay of an atom, and a source of radioactivity so weak that there was only a fifty per cent chance that a single atom would decay in any given hour. The cat and the mechanism were sealed inside the box, and the experiment ended after exactly an hour, when the box was opened again.
‘Schrödinger’s question was this,’ Fred Lehman said. ‘With a fifty per cent chance that an atom has decayed and triggered the mechanism that releases the cyanide, what’s the state of the cat immediately before the box is opened?’
Tom Waverly raised his hand, saying that he had a question of his own. What, he wanted to know, did this guy have against cats?
This was in the lecture theatre at Brookhaven. Fifteen young men and one young woman were scattered across tiers of seats, some assiduously taking notes, some hopelessly lost, all of them feeling the same electric thrill of participating in something tremendously secret and important. Tom Waverly was sprawled in a seat in the front row, his arms stretched across the backs of the seats to either side, smiling while he waited for Fred Lehman’s answer.
‘We’re not talking about a real cat in a real experiment,’ the physicist said. ‘The cat is a metaphor Schrödinger used to ridicule the suggestion that quantum theory could be used to make a complete description of physical reality. He claimed that before the box is opened, the cat must be in some indeterminate state, half-dead, half-alive. Since no living creature can be alive and dead at the same time, there must be something wrong with quantum theory.’
‘Of course it can’t be a real experiment,’ Tom Waverly said. Looking around, taking his time, building to his punchline. ‘I mean, have you ever tried to get a cat inside a box?’
In the warm dark, high above the ground in the branches of the oak tree, Stone smiled, remembering that Fred Lehman had waited out the laughter before explaining that the premise on which the thought experiment had been based was wrong, that the cat in the unopened box did not exist in an indeterminate state, neither wholly alive nor wholly dead, as Schrödinger asserted. Instead, the experiment caused the state of the observer to split into two - and it didn’t matter if the observer was the experimenter, the cat, or the radiation detector, as long as something or someone took a measurement that forced the quantum system of cat and box and cyanide apparatus to adopt a definite state. In one universe the observer opened the box and discovered a live cat; in the other, the box contained a corpse.
And this happened with every choice we ever make, Fred Lehman had told his class. In most cases the split was trivial and the two sibling universes quickly recombined. But if the observation caused a change big enough to affect other observers, recombination was delayed, and more and more differences accumulated in the states of the sibling universes until the split became permanent. A single probability sheaf split into two; history went in two different directions. In one the cat was alive; in the other, it was dead. In one, Khrushchev was assassinated and the Soviet generals ordered an atomic strike against the United States; in another, the assassination attempt failed or was stillborn, and Khrushchev withdrew the Soviet missiles and battlefield atomic weapons from Cuba. Each sheaf was woven from billions of closely related microhistories that branched and recombined and branched again as billions of observers made their trivial choices. But although most microhistories recombined almost immediately, a significant number did not, and in a few of those the split eventually became permanent.
Tom Waverly had loved the weirdness of quantum theory, but on a job he’d always done everything he could to avoid the dichotomous fate of Schrödinger’s cat, planning his hits to the last detail. It was pure bad luck that the cop had stumbled across him when he was moving into position. If he had shot only Eileen Barrie and Nathan Tate, the locals would have requested that a couple of NYPD murder detectives liaise with the Company team, purely as a formality, and left it at that. But Tom had killed a cop, the cop had been the mayor’s nephew, and now every one of New York’s finest was looking for him. Because one of their own had been murdered, they had permission to shoot on sight, and they were ready and willing to take care of business.
I’ll talk to Stone. But where, and when? Stone knew that he would have to think hard and fast, and hope for a lot of good luck, if he was going to catch up with Tom before the locals did.
He slid down the rope, put on his jacket, and walked back to the edge of the park and stood there for a few moments, looking at Eileen Barrie’s brownstone and the identical brownstones on either side, their bow windows, the balustrades that ran along the edges of their flat roofs. He slapped a lone, late mosquito and walked across the street. When he reached the taxi Linda cranked down her window and asked if he had found anything.
‘The report said that he got onto the roof of the house from one of the neighbouring brownstones.’
‘The one on the right. He got in through the back, picked the lock of the fire door in the basement, then picked the lock of the access door to the roof. The forensic team found fresh scratches on both of them. You think they missed something?’
‘I’m wondering why he didn’t stay up on the roof after he planted the napalm. He had an easy shot of the front door from across the street, but he had to evade police patrols to get into position. And in fact he didn’t evade them - he ran into that cop. If he’d stayed up on the roof, the shot would have been harder, but he wouldn’t have had to take the risk of moving into the park.’
‘He couldn’t stay up there because there were men posted on the roof of Dr Barrie’s brownstone.’
‘There were? How many?’
It hadn’t been in the report.
‘Two sharpshooters. They were watching the back yards and the roofs on either side.’
‘Were they in position all the time?’
‘Only when Dr Barrie was at home. When she went to work, a couple of officers stayed behind in her apartment, but the rest of the protection squad went with her. When she wanted to go home, the squad moved into position and checked everything out before they let her come back.’
‘She came home at around half-eight in the evening,’ Stone said. ‘So Tom had plenty of time to get up on the roof and plant the bomb and get out. But how did he know when she’d be coming home?’
‘He didn’t have to know the exact time. She always worked late.’
‘Are you sure?’
‘I tracked down one of the guys who’d been part of the protection squad and had a little chat with him. He said that the assignment was a nightmare because Dr Barrie kept crazy hours. Where are you going?’
‘I’m following a train of thought. Wait there. It won’t take long.’
Tom Waverly had left a message at his sniper’s position. He’d also spent some time on the roof of Eileen Barrie’s house, so he might well have left a message there, too. Stone unlocked the padlock and stripped away police tape, switched on the borrowed flashlight and stepped into the dark hallway. The ceiling had come down and there was a strong smell of smoke and burnt paint and charred wood. He picked his way through fallen plaster and puddles of water to the staircase and climbed all the way to the top, where the door to the building’s flat roof hung on a single hinge.
The cluster of brick chimneys had been collapsed by the explosion and the roof had caved in around them, exposing blackened beams. Stone skirted the hole, played the beam of the flashlight over the waist-high brickwork at the front of the roof but found nothing of interest, then cla
mbered onto the roof of the neighbouring brownstone, the one that Tom Waverly had broken into.
Stone paced the perimeter of the roof, shoes crunching on gravel, flicked the beam of the flashlight this way and that. There were fresh cigarette butts and a crumpled soft-drink can by the dividing wall, probably dropped by the police sharpshooters. There was a junked air conditioner. And there was an aluminium lawn chair set beside the balustrade at the front of the roof.
Although there could be a perfectly ordinary reason why there was a chair up here - perhaps someone liked to sit on the roof on fine summer days, taking in the view across the river to New Jersey and catching some rays - Stone got a little chill when he saw it. He walked over to the balustrade and looked down at the road, the chain of streetlights, the sawhorses blocking off the sidewalk in front of the brownstone, the taxi parked in front, its roof the colour of an old bruise in the sodium light. He sat in the chair, looked at the trees in the long narrow park, the streetlights of the Hudson Parkway, the New Jersey shore twinkling across the river . . . And remembered Tom Waverly sitting in a similar chair on his lawn at one or another of his barbecues, a drunkenly benevolent potentate watching his daughter search on her hands and knees for the coins he’d hidden in the grass. The chair set in what Tom claimed to be his favourite spot on Earth, where he liked to drink beer while watching the sun go down beyond the little lake; the search for coins scattered around it a little game that he and Linda loved to play.
A treasure hunt.
Stone trailed his fingers in the gravel either side of the chair, then dug deeper, his fingertips scraping tar paper beneath the gravel, finding nothing. But Tom had hidden coins under his chair too. Stone set the chair to one side and started to sift through the patch of gravel. Almost immediately, he found a scrap of thin card: the cover torn off a book of matches. It must have been placed there recently, because it was unwrinkled by time and weather. Chills chased up and down Stone’s spine when he held it in the beam of the flashlight and saw what was written there.
4
‘Is it your father’s handwriting?’
‘Definitely.’
Linda Waverly was examining the matchbook cover by the taxi’s interior light, holding it by its edges between thumb and forefinger. Printed in blue ballpoint on red card, half obscuring the logo of a bar, were a New York telephone number, the next day’s date, and 9.30 a.m. On the reverse, in the same blue ink: Adam - be there.
‘How could he be sure you’d find it?’ she said.
‘He knows how I work. He knew I would want to check out the scene, and guessed I’d spot that lawn chair and remember the game he used to play with you. It’s an easy reach,’ Stone said, and took the matchbook cover from her and dropped it into the breast pocket of his jacket.
He was excited and also - this he hadn’t expected - happy. Happy to be back in the field, happy to discover that his tradecraft wasn’t as rusty as he had feared. Although he’d only been in this sheaf for a few hours, he’d confirmed that Tom Waverly wanted to make contact, and had found a way of reaching out to him. Perhaps Tom wanted to turn himself in. Perhaps, in a day or two, Stone would be able to go back to New Amsterdam, and Susan and Petey.
Linda said, ‘We could call that number right now. See if he’s at home.’
‘It doesn’t say “Call me”. It says, “Be there”.’
‘How can you go visit a telephone number? Wait - it’s a pay phone, isn’t it? He wants to put you in some public place, so he can see if you’ve brought along company before he makes contact.’
‘That’s one possibility,’ Stone said. ‘Another is that he’ll call me and tell me where to go next. In any case, what I need to do now is find the location of the phone the number belongs to.’
‘The local office will have a reverse directory,’ Linda said. ‘I could call them right now—’
‘We’ll go check it out in person,’ Stone said. ‘The fewer people who know about this the better.’
‘And then what?’
‘Then you can take me back to my hotel.’
‘I want to be there when he calls you,’ Linda said. ‘I should be there.’
‘He asked to talk to me, Linda. I’m sorry, but that’s the only way—’
A couple of blocks down the dark street, two white sedans veered around a corner in a squeal of tyres, straightened out, and sped toward the taxi.
‘Friends of yours?’ Stone said.
‘Locals,’ Linda said, squinting into the glare of two sets of headlights. ‘I should call Mr Welch.’
She seemed angry and determined, not at all scared. She was her father’s daughter, all right.
‘Let’s see what they want first,’ Stone said, watching men in suits spill from the sedans, drawing guns as they went left and right, up the steps into the brownstone or across the street to the park. Locals, putting on a show.
A tall man in a brown chalkstripe suit walked up to the taxi, knocked on the window by Stone’s head and spoke his name, stepping back when Stone swung the door wide and climbed out.
‘Ed Lar,’ the man said. ‘We haven’t met, but I bet David Welch mentioned my name. And I surely know who you are. Mind showing me what you found?’
‘Mind showing me some ID?’ Stone’s heart was beating quickly, but he felt calm and cool; he had been half-expecting this.
Lar flipped his badge case in front of Stone’s face. The FBI officer was in his early forties, hair of no particular colour slicked back from a lean face with sharp cheekbones and bright blue eyes. ‘I know you found something up on that roof that my men missed, Mr Stone. I’m impressed. Truly.’
‘How were you keeping watch?’
Lar jerked a thumb at the black sky. ‘Technology borrowed from you guys. A couple of stealthed drones equipped with cameras that can count every hair on your head, parabolic dishes that can hear your every breath.’
‘It would have been easier to bug the taxi.’
‘Not as much fun, though. You can hand over that thing you found directly, or we can waste time downtown. Your call.’
‘In the spirit of cooperation,’ Stone said, and lifted the matchbook cover from his breast pocket with two fingers and held it out. ‘Be careful - there could be fingerprints.’
Lar took the scrap of cardboard from him and held it up in the glare of the headlights of the sedans. ‘I guess we both know who left this little love note.’
‘You’ll notice it’s addressed to me.’
‘Yeah, and you found it so easily I can’t help wondering if you and Waverly have something going on.’
‘He wanted me to find it. That’s why he left it where he did. And I can’t help wondering, Mr Lar, why his daughter is involved in the search for him.’
Lar glanced at Linda Waverly, who was watching them through the taxi’s open door, and said, ‘What do you mean?’
‘Was it David Welch’s idea to use her to try to flush out Tom Waverly, or did you two dream it up together?’
‘As far as I’m concerned, we don’t need either of you to find the son of a bitch,’ Lar said. He called over one of his officers, gave him the matchbook cover, and told him to find out who the phone number belonged to.
Stone said, ‘Tom Waverly wants to talk to me, Mr Lar, no one else. He wants me to be at that phone tomorrow, at nine-thirty. If I don’t answer, he’ll hang up. We’ll lose the chance to find out what he wants.’
Lar looked off at the park on the other side of the street. Flashlight beams danced in the darkness beneath the trees. ‘He wants to jerk our chains. To waste our time and resources by setting up a rendezvous he has no intention of keeping, because while we’re busy with his little diversion he’ll be attempting to slip past the security at Brookhaven.’
‘You could be right, but we can’t take the chance, can we?’ Stone said.
Lar pressed his eyes shut with the thumb and forefinger of his right hand. After a few moments, he said, ‘I’ll talk to Welch, and then I’ll want to talk to
you and Miss Waverly. I’ll get you a ride back to your hotel.’
‘Thanks for the offer, but I already have a ride.’
As they drove off, Stone asked Linda to call the local Company office and find the location of the phone whose number her father had written on the matchbook.
‘I thought you wanted to check it out in person?’
‘That was before Mr Lar muddied the water.’
Linda wedged her cell phone between her shoulder and ear as she drove, gave her name and the day code, then recited the telephone number. ‘I think you should pull up the phone company’s listings before you check the subscriber reverse directory.’
She listened for a few moments, then thanked the person at the other end of the line, switched off her phone, and told Stone, ‘It’s a pay phone, all right. One of six consecutive numbers in Duffy Square. Want to go check it out?’
‘Is Duffy Square north of Times Square here?’
Linda nodded. ‘Apart from the damage caused by the atomic bomb, everything’s more or less where it is in the Real. It’s good, isn’t it? That my father wants to talk, I mean.’
‘Of course it is.’ What else could he say? Besides, he wanted to believe it, too. He added, ‘I guess you’d better take me back to my hotel. I need to talk to Welch, get this thing with the locals straightened out.’
