There are a lot of outstanding crime writers working today in what I like to think of as the platinum age of mystery fiction, but none is more versatile than Lawrence Block, with only Donald E. Westlake as his equal.

Mr. Block’s finest novels are those about Matthew Scudder, a former New York City policeman with a serious drinking problem, who becomes a sort-of unofficial private eye (he does what private eyes do, mostly as favors to people he knows, but has no license); in the later books, he regularly attends AA meetings and successfully stays on the wagon.

This masterful series is dark, occasionally violent, and frequently poignant, as readers cannot help but come to know and, usually, develop affection for, the fully developed characters in the books who do not always enjoy happy lives. “Time to Murder and Create” (1977) and “Eight Million Ways to Die” (1982) were nominated for Edgars, and “A Dance at the Slaughterhouse” (1991) won one, but the best book in the series is “When the Sacred Ginmill Closes” (1987).

Much lighter are the charming novels in the 10-book series about Bernie Rhodenbarr, a burglar and bookstore owner, which began with “Burglars Can’t Be Choosers” (1977). Even frothier, but surprisingly entertaining, are the books about Evan Tanner — who has the bizarre sleep disorder of never needing any, and who finds himself in mostly humorous spy adventures — and the slightly dated tales about Chip Harrison, who is the assistant to a Nero Wolfe-like private detective. Mr. Block has also written numerous stand-alone novels as well as being a prolific short story writer.

Recently, he has focused his energies on another series character, John Paul Keller, who happens to be a hit man. The first three books about the stamp-collecting killer are short story collections disguised as novels: “Hit Man” (1998), “Hit List” (2000) and “Hit Parade” (2006), but the latest volume, “Hit and Run” (Morrow, 277 pages, $24.95) is a proper novel, and it’s a doozy.

The way Keller works is that his closest friend, Dot, acts as the middleman (please don’t get all PC on me, okay; middlewoman is a nonsense word) and calls him with the details of a job. She collects the money and takes a cut, while he travels to the job, does the deed, and comes home. He never meets the person ordering the hit, they don’t know who he is, and everyone stays nice and safe — except the target, of course.

Keller had pretty much decided to hang it up when he took a job that he didn’t want to take, feeling a little hinky about it, but it eventually went okay. Then, as “Hit and Run” opens, he finds he has to do it one more time and reluctantly sets out to take care of business.

He should have stayed home. It soon becomes apparent that he has been set up to take the fall for the assassination of an important politician and he’s in a lot of trouble. He’s 1,100 miles from home, he spent virtually all his cash for some rare stamps that he couldn’t live without, and his picture is on every front page and television station almost before the victim’s body is cold.

And that is only the beginning of his problems, which, in the way of all excellent thrillers, seem hopelessly insurmountable.

Most assuredly not in the manner of most excellent thrillers, however, is the exceptionally funny tone of the book. Comic novels often have situational humor, as in the works of Mr. Westlake and Carl Hiaasen, among others, while others have quotable funny lines, as in the works of Dave Barry and Loren D. Estleman.

Mr. Block does offer some funny lines. “Tell people something’s a long story,” Dot explains, “and they’re usually happy to let you get away without telling it.” And, Keller muses, “there came a time when stores began to stock bottled water, but the only people who bought it were the kind of people who ate sushi.” But the wry observations throughout, uttered by Keller as well as the other two main characters, will keep you smiling until your cheeks hurt.

Maybe the greatest way a writer can display his skill is to make a subject of which you thought you had not the slightest interest appear compelling — and you can be certain you will find in “Hit and Run” numerous paragraphs about philately suddenly to be too brief, as you just need to know more about the Swedish three-skilling orange.

Mr. Penzler is the proprietor of the Mysterious Bookshop in Manhattan and the series editor of the annual Best American Mystery Stories. He can be reached at ottopenzler@mysteriousbookshop.com.