I believe my subject is bewilderment,” said Donald Westlake. “But I may be wrong.”

Westlake, who published more than 100 books and wrote a dozen screenplays, was the very model of the writer as talented, disciplined, prolific professional. All but two of his books are fiction. A third of them feature either the ruthless criminal sociopath Parker or the hard-luck burglar John Dortmunder—each, in his way, also a consummate pro. Many regard the Parker novels, published under the pen name Richard Stark, as Westlake’s best—short and fierce, written in a bleak, stripped-down prose. The Dortmunder novels are genial, expansive comedies. Their typical arc: When his carefully planned caper-like robbery is sabotaged by bad luck, Dortmunder must do some fancy tap-dancing to get out of the resulting fix. His big score slips away and he is lucky to cover his costs.

The other sixty-plus books were issued under a mix of names, his own included, to avoid flooding the market and to create distinct brands. (Comfort Station, a pseudonymous parody of an Arthur Hailey blockbuster, even gets a cover blurb from Donald E. Westlake: “I wish I had written this book!”) Though most are crime novels of one sort or another, they are wildly various. Westlake once said that he would eventually like to write “one of everything,” not excluding “an opera and a Hallmark card.” Some examples plucked at random from the shelves of my local library: The Hook, a dark tale about two men