Sweet, Sweet Poison

First victim in this fresh, entertaining mystery is a watchdog named Sadie, owned by Al and Sylvie Zukal, two likable, spectacularly vulgar kvetches from the Bronx who invested some recent lottery winnings on a rural estate in Spender's Ferry, N.Y. After the Zukals' young friend David dies, the well-oiled, older detective team of Charlie Meiklejohn and Constance Leidl ( Small House ; The Hamlet Trap ) begins to question the conclusions of the local sheriff, who labels these and additional inventive killings--by poison, drugs, bees and gas--accident or suicide. Charlie and Constance turn up a barrelfull of suspects: kingmaker Warren Wollander; his childish daughter and her latest guru, a smarmy evangelist; and a gaggle of agrarian scientists, including Warren's wife. The smooth, easy appeal of SF writer Wilhelm's blend of suspense and humor goes awry only in her hamfisted portrait of the Zukals. (Aug.)