When you suspect that your ex-wife's Valium-aided drowning last year was no accident, but the only evidence your three private eyes have dug up implicates you as the killer, who do you turn to in desperation? Why, ad executive Simona Griffo (The Trouble with a Bad Fit, 1996, etc.), who, despite her demurrals, has gotten so self-confident that she's handing out business cards (""Dim Sim Detective Agency"") that she and her Russian partner Dmitri K. have printed up. But before she can crack the mystery behind Polly Pynes's death, her client, advertising wizard Bud Warren, vanishes, only to turn up as full of ocean water as his ex. Was he killed for control of his top-flight ad agency, his $1 million beachfront property in East Hampton, or something more personal? And which of the six suspects he listed (including his own daughter) did him in? The answer will surprise most readers, even though Crespi's conscientious plotting never makes summer seem all that hot.