The chatty, urban narrator here is Henry Grace, 42, a minor playwright who 20 years ago had a summer-stock menage a trois with chum Turner and beautiful Sarah. But Sarah married Turner, and that was that. . . till a recent, rekindled Sarah/Henry affair. So, when Sarah is discovered murdered, Henry is sure that Turner did it--even though the two men were together, at a movie, at the time of the crime! And when Henry is mailed (by an anonymous source) photos of Turner in a mini-orgy, he grabs at this clue and sets out to track down the other bodies in the photo: with dubious ease he finds one of them in Miami (the man is promptly killed) and then traces the other one--a sexy would-be actress--to a secluded upstate-NY cabin. What's the connection to the murder? Well, the orgy-mates were Turner's unsuspecting accomplices in faking his alibi--so now he's out to kill them off. And the book's disappointing last section (reading like a corny melodrama) is an endlessly stretched-out siege at the cabin: psychotic Turner vs. Henry, with the sexy girl in the middle. Agreeably offbeat at the start, then, but increasingly implausible and overwrought.