The return of Claire Malloy--the author's smart, slightly cynical small-town book-store owner; mother of teen-age daughter Caron; girlfriend of local police lieutenant Peter Rosen--who has now been inveigled into helping with the annual Miss Thurberfest Beauty Pageant. Reigning winner Cyndi Jay--managed by trainer Eunice Allingham, who has visions of the Big One in Atlantic City--seems sweetly ingenuous and an unlikely target for the series of minor but nasty incidents that befall her, mostly at the Thurber Street Theatre, newly renovated by curmudgeon David McWethy. Then, with the arrival of the M.C.--smooth, dimpled State Senator Steve Stevenson, up for reelection--impeccably correct wife Patti; and aide Warren, those incidents escalate dramatically, ending in death for Cyndi in a gas-filled dressing room. But Claire, unable to keep her detecting instincts at bay (Strangled Prose, etc.) despite Rosen's wrath, and after a second killing, gets her murderer in a fairly tense, fairly believable finale. The story--a mix of wayward passions, politics and blackmail--sags at times, but Hess's style--that of a more worldly Erma Bombeck--rarely flags. Her unbedazzled account of the beauty pageant and its participants is a sendup but without cruelty. Amiable entertainment with an edge.