He was completely focused on squeezing the life from me as I moved my right hand inside my jacket and felt the cool grip of the Smith & Wesson. I thought I was about to black out when I managed to wrench it free and move my arm enough to stick the muzzle into the soft flesh beneath Billy's jaw. The red light in his eyes flared briefly and then began to fade. The pressure on my neck eased, the knife slid out of the wound and I slumped to the floor. My throat ached as I pulled shallow, rattling breaths into my starved lungs. I kept the gun on Billy but he had turned away. Now that his tide of rage had begun to ebb, he seemed unconcerned about the gun, and about me. He took a cigarette from a pack of Marlboros, lit up, then offered the pack to me. I shook my head in refusal until the pain in my ear started raging again. I decided to stop shaking my head.

"Why'd you put the lock on me?" asked Billy in an aggrieved tone. He looked at me and there was genuine hurt in his eyes. "You shouldn't have put the lock on me."

The guy was certainly a character. I drew some more breaths, deeper now, and spoke. My voice sounded hoarse and my throat felt as if someone had rubbed grit into it. If Billy had been less of a child, I might have used the butt of the gun on him.

"You said you were going to get a baseball bat and beat the living shit out of me, as I recall," I said.

"Hey, you were being rude," he said and the red light seemed to glow again for a brief moment. I still had the gun pointed at him and he still didn't seem concerned. I wondered if he knew something about the gun that I didn't. Maybe the stench in the trailer was rotting the bullets as we spoke.

Rude. I was about to shake my head again when I remembered my ear and decided that it might be better, all things considered, to keep my head steady. I had come to visit Billy Purdue as a favor to Rita, now his ex-wife, who lived in a small apartment over on Locust Street in Portland with her two-year-old son, Donald. Rita had been granted her divorce six months before and since then Billy hadn't paid over a nickel of child support. I knew Rita's family when I was growing up in Scarborough. Her father had died in a botched bank raid in Bangor in '83 and her mother had struggled and failed to keep her family together. One brother was in jail, another was on the run from drug charges and Rita's elder sister was living in New York and had cut off all contact with her siblings.

Rita was slim and pretty and blonde but already the raw deal life had dealt her was taking its toll on her looks. Billy Purdue had never hit her or physically abused her, but he was prone to black rages and had destroyed the two apartments in which they had lived during their marriage, setting fire to one after a three-day binge in South Portland. Rita had woken up just in time to get her then one-year-old son out, before hauling Billy's unconscious body from the apartment and setting off the alarm to evacuate the rest of the building. She filed for divorce the next day.

Now Billy skulked in his bullet-shaped trailer and lived a life that was on nodding terms with poverty. During the winter he did some lumber work, cutting Christmas trees or heading farther north to the timber company forests. The rest of the time he did what he could, which wasn't a lot. His trailer stood on a patch of land owned by Ronald Straydeer, a Penobscot Indian from Old Town who had settled in Scarborough after returning from Vietnam. Ronald was part of the K-9 corps during the war, leading army patrols down jungle trails with his German shepherd dog Elsa by his side. The dog could smell Vietcong on the wind, Ronald once told me, even found freshwater once when a platoon ran dangerously low. When the Americans pulled out, Elsa was left behind as "surplus equipment" for the South Vietnamese army. Ronald had a picture of her in his wallet, tongue lolling, a pair of dog tags hanging from her collar. He figured the Vietnamese ate her as soon as the Americans left, and he never got himself another dog. Eventually, he got Billy Purdue instead.

Billy knew his ex-wife wanted to move to the West Coast and start a new life and that she needed the money Billy owed her to do that. Billy didn't want her to go. He still believed that he could salvage their relationship, and a divorce and an order preventing him from going within one hundred feet of his ex-wife hadn't altered this belief.

It was about the time that I told Billy Purdue that she wasn't coming back to him and that he had a legal obligation to pay her the money she was owed that Billy had gone for the baseball bat and things had fallen apart.

"I love her," he said, puffing on his cigarette and sending twin columns of smoke shooting from his nostrils like the exhalations of a particularly mean-tempered bull. "Who's gonna look out for her in San Francisco?"

I struggled to my feet and wiped some of the blood from my cheek. The sleeve of my jacket came back damp and stained. It was lucky my jacket was black, although the fact that I considered that lucky said a lot about the kind of day I was having.

"Billy, how can she and Donald survive if you don't pay her the money the judge told you to pay?" I replied. "How's she going to get by without that? If you do care about her, then you have to pay her."

He looked at me and then looked at his feet. His toe shifted on the filthy linoleum.

"Sorry I hurt you, man, but…" He reached behind his neck and scratched at his dark, unruly hair. "You gonna go to the cops?"

If I was going to the cops, I wouldn't tell Billy Purdue. Billy's regret was about as genuine as Exxon's when the Valdez went down. Plus, if I went to the cops Billy would be locked up and Rita still wouldn't get her money. But there was something in his tone when he asked about the cops, something that I should have picked up on but didn't. His black T-shirt was soaked with sweat, and there was mud caked at the cuffs of his pants. He had so much adrenaline coursing through his system, he made ants look calm. I should have known that Billy wasn't concerned about the cops because of some assault beef, or unpaid child support. Hindsight: it's a wonderful thing.

"If you pay the cash, I'll let it go," I said.

He shrugged. "I ain't got much. Ain't got a thousand dollars."

"Billy, you owe nearly two thousand dollars. I think you're missing the point here."

Or maybe he wasn't. The trailer was a dump, he drove a Toyota with holes in the floor and he made one hundred, maybe one-fifty, each week hauling junk and lumber. If he had two thousand dollars, he'd be someplace else. He'd also be somebody else, because Billy Purdue was never going to have two thousand dollars to his name.

"I got five hundred," he said eventually, but there was something new in his eyes as he said it, a kind of low cunning.

"Give it to me," I replied.

Billy didn't move.

"Billy, if you don't pay me the cops are going to come and lock you up until you do pay. If you're locked up, you can't make any cash to pay anyone and that looks like a vicious circle to me."

He considered that for a time, then reached beneath the filthy sofa at the end of the trailer and produced a crumpled envelope. He turned his back to me and counted out five hundred-dollar bills, then replaced the envelope. He handed over the cash with a flourish, like a magician producing someone's wristwatch after a particularly impressive conjuring trick. The bills were brand new, consecutively numbered. From the look of the envelope, they had left a lot of friends behind.

"You go to the cash machine over at Fleet Bank, Billy?" I asked. It seemed unlikely. The only way Billy Purdue would get money from a cash machine was by breaking it out of the wall with a bulldozer.

"You tell her something from me," he said. "You tell her that maybe there's more where this came from, understand? You tell her that maybe I ain't such a loser no more. You hear me?" He smiled a knowing smile, the kind of smile someone really dumb shoots at you when he thinks he knows something that you don't. I figured that if Billy Purdue knew it, then it wasn't anything that should concern me. I was wrong.