The setting for this breezy, likable mystery debut is a fading law-patent finn on 23rd St. in Manhattan--where narrator Bonnie Indermill is the much put-upon office manager. So it's lucky Bonnie who gets called to identify the body when Albert Janowski--sleazy attorney, son-in-law of the firm's most senior partner--turns up murdered in a Tenth Avenue ""sex hotel,"" with kinky (nudity, bondage) trimmings. Was Janowski killed because of his apparent secret-life as a swinger? Or because his wife--now a very merry widow, who takes Bonnie for a horsy lunch at Tavern on the Green--lusted for freedom? Those are two of the possibilities considered by cop Tony LaMarca, with whom Bonnie begins a tentative romance/partnership. But there are also motives glimmering in the law-firm's past: the 1962 drowning of the firm's founder; the forgotten patents of a crazed old inventor. And when Bonnie's low-key snooping starts producing results, she becomes the rather pathetic killer's next target. Standard plotting, complete with damsel-in-distress vignettes--but first-novelist Berry finds unforced amusement in a shabby law-firm's foibles. And, despite some overfamiliar touches (e.g., the Mom back home who wishes Bonnie had a husband and Tupperware), Bonnie's wry, N.Y.-survivor narration keeps things bouncing along in smart--but never smart-alecky--style.