The lieutenant drove an unmarked rust-colored car this time. When he stopped at the curb and Tess got in to fasten her seatbelt, she noticed that his creased brow was beaded with sweat. His blue suitcoat was lumped beside him. The front of his wrinkled white shirt and the underarm she could see were dark with moisture.

'Sorry.' He coughed. The windows were open, but the only breeze on this sultry smog-hazed June afternoon came from passing cars. 'The air conditioner doesn't work.'

'I'll adjust.'

'Good. That makes one of us.'

'Asthma, you said?'

'What?'

'Your cough.'

'Oh.' Craig steered into traffic. 'Yeah, my cough. That's what my doctor tells me. Asthma. Allergies. This town's killing me.'

'Then maybe you should move.'

'Sure. Like to someplace wholesome? Like to Iowa? What's that line in the movie? Field of Dreams. Yeah, that's the movie. "Is this heaven?" and Kevin Costner says, "No, it's Iowa." Cornfields? Give me a break. I was raised here. This is heaven.' Craig frowned, his voice dropping. 'Or at least, it used to be.'

He turned east off Broadway.

'We're heading in the same direction we did last time.' Tess became rigid. 'Don't tell me we're going back to-'

'The morgue?' Craig shook his head and coughed. 'I'd have warned you. No, we'll be driving up First Avenue again.'

'To Carl Schurz Park? But I don't want to-'

'No, not there either. Let me do this my way, all right? So I can explain and prepare you? And don't frown. I swear, cross my heart, you won't see anything gross.'

'You're positive?'

'I'm not saying it won't disturb you, but I guarantee it won't make you sick. On the other hand… Okay, here's the deal. You told me your friend was different? That's an understatement. According to the FBI, he doesn't exist.'

'Doesn't…? What are you…?'

'We sent your friend's name to the Bureau to help them find a match for the fingerprints on the corpse's unburned left hand. They searched their computers for a file on Joseph Martin. No surprise. It's a common name. There are plenty of Joseph Martins. What is surprising is that none of the fingerprints in those files matched the fingerprints we sent to the Bureau.'

'But surely not everybody has fingerprints in the Bureau's files.'

'Right.' Craig continued toward First Avenue. 'So the next step is to check with Social Security, to match the number your friend gave his employer with the names and addresses on their list.'

'And?'

Craig steered around a UPS truck, its driver hurrying to make a delivery. 'And? There is a Joseph Martin with that number. The trouble is, he lives in Illinois. Or used to live in Illinois. Because – and this took several phone calls – Joseph Martin who has that social security number died in nineteen fifty-nine.'

'There's some mistake.'

Craig shook his head. 'I doublechecked. The result came up the same. Joseph Martin – your Joseph Martin – should have quit fooling everybody. He should have done the decent thing, stretched out on the floor, crossed his arms, stopped breathing, and been as dead as the Joseph Martin who's in a cemetery in Illinois.'

While Craig reached First Avenue and headed north, Tess felt pressure behind her ears. 'You're telling me Joseph assumed the identity of a dead man?'

'Actually dead child. Infant. Remind me – how old did you estimate Joseph to be?'

'Early thirties.'

'Let's make it thirty-two,' Craig said. 'Because that's how old the other Joseph Martin would be today if he hadn't been killed in a car crash along with his parents in 'fifty-nine.'

'And I'll bet there were no surviving close relatives.'

'Oh?' Craig assessed her. 'You understand how this is done?'

Tess spread her hands. 'Someone who wants a new identity chooses a community at random and checks the obituaries in the local paper for the year in which he himself was born. He looks for an infant who died that year and was either an orphan or was killed along with his immediate family. That way, he doesn't look older or younger than he says he is, and there's no one who can contradict his claim to be that person. The next step is to find out where the child was born. That information is often in the obituary: "so-and-so was born in this-or-that city." The person seeking a new identity then writes to the courthouse in that city, tells its record office that he lost his birth certificate, and asks for a replacement. People often lose their birth certificates. It's not unusual for someone to ask for another copy, and clerks almost never bother to check if the name on the birth certificate matches the name of someone who's dead. As soon as he gets the birth certificate, the person sends a photostat to the Social Security office, explains that he lived abroad for many years and didn't need a Social Security number but now he does. The Social Security office seldom objects to such a request. With a birth certificate and a Social Security number, the person can get a passport, a driver's licence, a credit card, all the documents he needs to appear legitimate, to enter the system, get a job, pay taxes, etc.'

'Very good,' Craig said, continuing northward. 'I'm impressed.'

'Reporters pick up all kinds of information.' Tess certainly didn't intend to add that the real way she'd learned about assuming false identities was by overhearing her father's phone conversations with business associates.

Craig brooded, passing Forty-Ninth Street. 'With some cooperation from the federal government, I've been able to learn that Joseph began to use his assumed identity in May of last year. That's when he first started paying income taxes and Social Security. Since then, he's had two jobs, not counting his present one. The first was in Los Angeles, the second in Chicago. Obviously he didn't want to stay in any place too long, and he felt the need to put a lot of miles between one location and another. In each case, he worked for a video documentary company.'

'Okay.' Breathing too fast, Tess concentrated not to hyperventilate. 'So Joseph had something to hide. Everything about him was a lie. That explains why he didn't want me to get close to him. The question is, what the hell was he hiding?'

'Maybe you'll be able to tell me when you see where I'm taking you. Certainly I can't figure it out,' Craig said.

'Figure out what? Where are we going?'

'No. Not yet.'

'What?'

The problem is… See, first I have to explain some other things.'

Tess raised her arms in exasperation.

'Be patient. When I talked to the accountant where Joseph worked,' Craig said, 'I asked to see the paychecks he cashed. They're too large for a supermarket or a liquor store to accept them. He'd have needed to take them to a bank. And the bank would have sent the cancelled checks to his employer's bank, which in turn would have sent them to the employer's accountant. As it happens, Joseph cashed all his checks at the same bank. Back there.' Craig pointed. 'We just passed the bank on Fifty-Fourth Street.'

'So you went to the bank, showed them a court order allowing you access to their records, and examined Joseph's account,' Tess said.

Craig assessed her again. 'You'd have made a good policeman.'

'Police woman.'

Craig ignored her correction. 'Yes. That's what I did. I went to the bank, and the address they had for Joseph was the mail service on Broadway. That was also the address he told the bank to print on his checks. No surprise. What was surprising is that the microfilm records of Joseph's cancelled checks show that he hadn't made any payments for electricity or rent. Obviously he had to live somewhere and pay his utilities, so how was he keeping his landlord and Con Edison happy? Turns out, every month he sent a check for thirteen hundred dollars to a man named Michael Hoffman. Now take a guess who Hoffman is.'