This third outing for San Francisco shamus Nick Polo (Polo, Solo; Polo Anyone?) begins, with striking similarity to Robert Reeves' Doubting Thomas (1985), when Nick--off-duty--finds a corpse in the men's room at the Golden Gate racetrack. And the dead man just happens to be old bookie Johnny Aiello, the legman for Nick's Uncle Dominic, a relatively honest and upright bookmaking-kingpin. Why did someone murder harmless old Johnny? Apparently to prevent him from placing bets that would have lowered the odds on a long-shot that won big: Trish's Lamb Chop, a horse trained by bar-and-stable owner Donald Jepson. Then Jepson's killed, too, in a crazed-horse ""accident."" So Nick--when not cooking (ti la Spenser) or bedding girlfriend Jane--is soon tracking down the bettors who made a fortune on Lamb Chop's unexpected (and semi-rigged) victory. And after the trail leads to a nasty rich-kid, a grossly thuggish bartender, and two more murder victims, Nick confronts the villains in a series of violent showdowns. . .and finally arranges for the bad guys to more or less self-destruct. A thin, quickly solved puzzle, followed by lots of action-filler--but once again Kennealy offers a modest, loosely appealing mix: grimily intriguing San Francisco venues, coarsely amusing people, and Nick's breezy, occasionally raunchy narration.