Back in November, Richard and Amanda Thurman had attended a small dinner party on Central Park West. They left the party shortly before midnight. It was a pleasant night; it had been unseasonably warm all week, so they elected to walk home.

Their apartment occupied the entire top floor of a five-story brownstone onWest Fifty-second Street between Eighth and Ninth Avenues. The ground floor housed an Italian restaurant, while a travel agent and a theatrical broker shared the second floor. The third and fourth floors were both residential. There were two apartments on the third floor, one housing a retired stage actress, the other a young stockbroker and a male model. The fourth floor held a single apartment; the tenants, a retired attorney and his wife, had flown toFlorida on the first of the month and wouldn't be back until the first week in May.

When the Thurmans got home, somewhere between twelve and twelve-thirty, they reached the fourth-floor landing just as a pair of burglars emerged from the attorney's empty apartment. The burglars, two large and muscular white males in their late twenties or early thirties, drew guns and herded the Thurmans into the apartment they had just ransacked. There they relieved Richard of his watch and wallet, took Amanda's jewelry, and told the two that they were a pair of worthless yuppies and they deserved to die.

They gave Richard Thurman a beating, tied him up and taped his mouth. Then they sexually assaulted his wife in front of him. Eventually one of them struck Richard over the head with what he believed was a crowbar or pry bar and he lost consciousness. When he came to the burglars were gone and his wife was lying on the floor across the room, nude and apparently unconscious.

He rolled off the bed onto the floor and tried kicking at the floor, but it was thickly carpeted and he couldn't make enough noise to attract the attention of the tenant in the apartment below. He knocked over a lamp but no one responded to the noise it made. He made his way over to where his wife was lying, hoping to arouse her, but she did not respond and did not appear to be breathing. Her skin felt cool to him and he was afraid that she was dead.

He couldn't free his hands and his mouth was still taped. It took some doing to loosen the tape. He tried shouting but no one responded. The windows were closed, of course, and the building was an old one, with thick walls and floors. He finally managed to upend a small table and knock a telephone down onto the floor. Also on the table was a metal tool that the attorney used to tamp down the tobacco in his pipe. Thurman gripped that between his teeth and used it to ring 911. He gave the operator his name and address and said he was afraid his wife was dead or dying. Then he passed out, and that's how the police found him.

THAT was on the second weekend in November, Saturday night and Sunday morning. On the last Tuesday in January, I was sitting in Jimmy Armstrong's at two in the afternoon drinking a cup of coffee. Across the table from me sat a man about forty years old. He had short dark hair and a closely trimmed beard that was showing a little gray. He wore a brown tweed jacket over a beige turtleneck. He had an indoor complexion, no rare thing in the middle of aNew York winter. His gaze, behind metal-framed eyeglasses, was thoughtful.

"I think that bastard killed my sister," he said. The words were angry but the voice was cool, the inflection level and neutral. "I think he murdered her and I think he's getting away with it, and I don't want that to happen."

Armstrong's is at the corner of Tenth and Fifty-seventh. It's been there a few years now, but before then it was onNinth Avenue between Fifty-seventh and Fifty-eighth, in premises now occupied by a Chinese restaurant. In those days I just about lived in the place. My hotel was right around the corner, and I ate one or more meals a day there, met clients there, and spent most of my evenings at my usual table in the back, talking with people or brooding by myself, drinking my bourbon neat or on the rocks or, as an aid to staying awake, mixing it with coffee.

When I stopped drinking, Armstrong's was at the top of my unwritten list of people, places, and things to avoid. That became easier to do when Jimmy lost his lease and moved a block west, out of my usual daily traffic pattern. I didn't go there for a long time, and then a sober friend suggested we stop there for a late bite, and since then I've probably had half a dozen meals there. They say it's a bad idea to hang out in ginmills when you're trying to stay sober, but Armstrong's felt more like a restaurant than a ginmill anyway, especially in its current incarnation with its exposed brick walls and potted ferns overhead. The background music was classical, and on weekend afternoons they had live trios playing chamber music. Not exactly your typical Hell's Kitchen bucket of blood.

When Lyman Warriner said he was down fromBoston I suggested we meet at his hotel, but he was staying at a friend's apartment. My own hotel room is tiny, and my lobby is too shabby to inspire confidence. So once again I had picked Jimmy's saloon as a place to meet a prospective client. Now a baroque woodwind quintet played on the sound system while I drank coffee and Warriner sipped Earl Grey tea and accused Richard Thurman of murder.

I asked him what the police had said.

"The case is open." He frowned. "That would seem to suggest that they're working on it, but I gather it means the reverse, that they've largely abandoned hope of solving it."

"It's not that cut-and-dried," I said. "It usually means the investigation is no longer being actively pursued."

He nodded. "I spoke to a Detective Joseph Durkin. I gather the two of you are friends."

"We're friendly."

He arched an eyebrow. "A nice distinction," he said. "Detective Durkin didn't say that he thought Richard was responsible for Amanda's death, but it was the way he didn't say it, if you know what I mean."

"I think so."

"I asked him if he could think of anything I might do to help resolve the situation. He said that everything that could be done through official channels had been done. It took me a minute before I realized he couldn't specifically suggest I hire a private detective, but that was where he was leading me. I said, 'Perhaps someone unofficial, say a private detective- ' and he grinned as if to say that I'd caught on, that I was playing the game."

"He couldn't come right out and say it."

"No. Nor, I gather, could he come right out and recommend your services. 'As far as a recommendation's concerned, all I'm really supposed to do is refer you to the Yellow Pages,' he said. 'Except I should say that there's one fellow right here in the neighborhood who you won't find in the book, on account of he's unlicensed, which makes him very unofficial.' You're smiling."

"You do a good Joe Durkin imitation."

"Thank you. Pity there's not much call for it. Do you mind if I smoke?"

"Not at all."

"Are you sure? Almost everyone's quit. I quit, but then I started again." He seemed about to elaborate on that, then took out a Marlboro and lit it. He drew in the smoke as if it were something life-sustaining.

He said, "Detective Durkin said you were unorthodox, even eccentric."

"Were those his words?"

"They'll do. He said your rates are arbitrary and capricious, and no, those weren't his words either. He said you don't furnish detailed reports or keep track of expenses." He leaned forward. "I can live with that. He also said when you get your teeth in something you don't let go, and that's what I want. If that son of a bitch killed Amanda I want to know it."

"What makes you think he did?"

"A feeling. I don't suppose that's terribly scientific."