“That’s a comfort.”

“How many people have you killed, Keller?”

“What kind of a question is that?”

“And do you sense a burst of homicidal rage in your future?”

“Not really.”

“Then I’d say you can relax. You may have a murderer’s thumb, but I don’t think you have to worry about it.”

He wasn’t worried, not exactly. But he would have to say he was puzzled. How could a man have a murderer’s thumb all his life and be unaware of it? And, when all was said and done, what did it mean?

He had certainly never paid any particular attention to his thumb. He had been aware that his two thumbs were not identical, that there was something slightly atypical about his right thumb, but it was not eye-catchingly idiosyncratic, not the sort of thing other kids would notice, much less taunt you about. He’d given it about as much thought over the years as he gave to the nail on the big toe of his left foot, which was marked with ridges.

Hit man’s toe, he thought.

He was poring over a price list, France amp; Colonies, wrestling with some of the little decisions a stamp collector was called upon to make, when the phone rang. He picked it up, and it was Dot.

He made the usual round-trip by train, Grand Central to White Plains and back again. He packed a bag before he went to bed that night, and in the morning he caught a cab to JFK and a plane to Tampa. He rented a Ford Escort and drove to Indian Rocks Beach, which sounded more like a headline in Variety than a place to live. But that’s what it was, and, though he didn’t see any Indians or rocks, it would have been hard to miss the beach. It was a beauty, and he could see why they had all these condos on it, and vacation time-shares.

The man Keller was looking for, an Ohioan named Stillman, had just moved in for a week’s stay in a beachfront apartment on the fourth floor of Gulf Water Towers. There was an attendant in the lobby, Keller noticed, but he didn’t figure to be as hard to get past as the Maginot Line.

But would he even need to find out? Stillman had just arrived from sunless Cincinnati, and how much time was he going to spend inside? No more than he had to, Keller figured. He’d want to get out there and soak up some rays, maybe splash in the Gulf a little, then zone out some more in the sun.

Keller’s packing had included swim trunks, and he found a men’s room and put them on. He didn’t have a towel to lie on-he hadn’t taken a room yet-but he could always lie on the sand.

It turned out he didn’t have to. As he was walking along the public beach, he saw a woman approach a man, her hands cupped. She was holding water, and she threw it on the man, who sprang to his feet. They laughed joyously as he chased her into the surf. There they frolicked, perfect examples of young hormone-driven energy, and Keller figured they’d be frolicking for a while. They’d left two towels on the sand, anonymous unidentifiable white beach towels, and Keller decided one was all they needed. It would easily accommodate the two of them when they tired of splashing and ducking one another.

He picked up the other towel and walked off with it. He spread it out on the sand at the private beach for Gulf Water Towers residents. A glance left and right revealed no one who in any way resembled George Stillman, so Keller stretched out on his back and closed his eyes. The sun, a real stranger to New York of late, was evidently wholly at home in Florida, and felt wonderful on his skin. If it took a while to find Stillman, that was okay with him.

But it didn’t.

Keller opened his eyes after half an hour or so. He sat up and looked around, feeling a little like Punxsutawney Phil on Groundhog Day. When he failed to see either Stillman or his own shadow, he lay down and closed his eyes again.

The next time he opened them was when he heard a man cursing. He sat up, and not twenty yards away was a barrel-chested man, balding and jowly, calling his right hand every name in the book.

How could the fellow be that mad at his own hand? Of course he might have a murderer’s thumb, but what if he did? Keller had one himself, and had never felt the need to talk to it in those terms.

Oh, hell, of course. The man was on a cell phone. And, by God, he was Stillman. The face had barely registered on Keller at first, his attention held by the angry voice and the keg-shaped torso thickly pelted with black hair. None of that had been visible in the head-and-shoulders shot Dot had shown him, and it was what you noticed, but it was the same face, and here he was, and wasn’t that handy?

While Stillman took the sun, Keller did the same. When Stillman got up and walked to the water’s edge, so did Keller. When Stillman waded in, to test his mettle in the surf, Keller followed in his wake.

When Keller came ashore, Stillman stayed behind. And, by the time Keller left the beach, carrying two towels and a cellular phone, Stillman had still not emerged from the water.

Why a thumb?

Keller, back in New York, pondered the question. He couldn’t see what a thumb had to do with murder. When you used a gun, it was your index finger that gave the trigger a squeeze. When you used a knife, you held it in your palm with your fingers curled around the handle. Your thumb might press the hilt, as a sort of guide, but a man could have no thumbs at all and still get the business end of a knife to go where he wanted it.

Did you use your thumbs when you garroted somebody? He mimed the motion, letting his hands remember, and he didn’t see where the thumbs had much of a part to play. Manual strangulation, now that was different, and you did use your thumbs, you used all of both hands, and would have a hard time otherwise.

Still, why a murderer’s thumb?

“Here’s what I don’t get,” Dot said. “You go off to some half-a-horse town at the ass end of nowhere special and you poke around for a week or two. Then you go to a vacation paradise in the middle of a New York winter and you’re back the same day. The same day!”

“I had an opening and I took it,” he said. “I wait and maybe I never get that good a shot at him again.”

“I realize that, Keller, and God knows I’m not complaining. It just seems like a shame, that’s all. Here you are, the two of you, fresh off a couple of planes from the frozen North, and before either one of you gets the chill out of your bones, you’re on a flight to New York and he’s rapidly approaching room temperature.”

“Water temperature.”

“I stand corrected.”

“And it was like a bathtub.”

“That’s nice,” she said. “He could have opened his veins in it, but after you held his head underwater for a few minutes he no longer felt the need to. But couldn’t you have waited a few days? You’d have come home with a tan and he’d have gone into the ground with one. You meet your Maker, you want to look your best.”

He glanced over at the television set, where a thin young man and a fat young woman were having a food fight. Intermittently a couple of burly men in jumpsuits restrained one or both of them, only to let them resume pelting one another with bowls of salad.

“Jerry Springer,” Dot said. “It’s sort of a combination of Family Court and WWF Wrestling.”

“How come you’ve got the sound off?”

“Believe me, it’s worse if you can hear them.”

“I can see how it would be,” he said. “But lately you’ve always got the sound off. The picture on and the sound off.”

“I know.”

“If you had it the other way around I’d say you invented the radio. This way, what? The silent film?”

“I hardly look at it, Keller. Then what’s it doing on-is that what you were going to ask?”

“I might have.”

“For years,” she said, “I only put the set on to watch something. I had my afternoon programs, and then for a while I got hooked on those home shopping channels.”