John Keller, professional hit man, is on his way to Des Moines to take a life – one last job before retiring to spend more time with his stamp collection.

Keller is the consummate pro. He’s killed hundreds of times, yet the police don’t even know his name. But you know how it is with that final job. Something is bound to go wrong. Keller’s seen enough TV crime dramas to know it, too. He even jokes about it, but you can tell the thought has him on edge.

In Des Moines, Keller’s contact points out the target but tells him the timing is wrong, that he should hang out for a few days and wait for the go-ahead. The contact also gives Keller his choice of murder weapons: a Glock semiautomatic or a revolver. Keller hefts them both, then choses the revolver.

A few days later, as Keller is still waiting for the word, a candidate campaigning in Iowa’s presidential primary is assassinated. With a Glock. And Keller’s prints are on the gun.

Realizing he’s been set up as the fall-guy, Keller runs for his life.

It’s the biggest fix Keller’s been in since Lawrence Block introduced him with 9 short stories for Playboy magazine more than a decade ago. The stories formed the basis for “Hit Man,” the first Keller novel, in 1998. “Hit and Run” (William Morrow, $24.95) is the fourth in the series from this prolific writer whose work also includes crime novels featuring four other series characters: Matthew Scudder, Evan Tanner, Chip Harrison and Bernie Rhodenbarr.

Like Keller, Block has been practicing his craft for a long time and is every bit as good at it. In fact, he’s such a superb storyteller that in “Hit and Run,” he seems to be showing off.

Virtually all the action in the book occurs in the first 22 pages and the final 40, leaving 222 pages in which not much happens. Keller moves around from place to place, uses his skills to build a new identity, eventually settles down in a new life as a carpenter in New Orleans, and meets a nice young woman.

It should be deadly dull, but it’s not. The crisp prose, the pitch-perfect dialogue and richly drawn characters make the book hard to put down. And, of course, you sense that by the end of the book, something unexpected is going to happen.