Books: A Round of Ambrose

THE NAKED VILLANY (271 pp.)—Jocelyn Davey—Knopf ($3.50).

Among fictional detectives, the most numerous are the Newton types. Popped on the head by the apples of sinister circumstance, they gravitate to solutions by prodigies of deduction. Amateur Detective Ambrose Usher, an Oxford don, is different. Says a baffled friend: "Things don't happen to you: you happen to things. You walk into a perfectly quiet situation . . ." Replies Ambrose: "Oh, dear. Yes, yes. It may be. I'm the apple itself, perhaps. What an awkward role . . ."

Short, apple-round and learnedly garrulous, Ambrose ambles...