This third outing for San Francisco p.i. Jeremiah St. John (St. John's Baptism, According to St. John) begins with a solidly intriguing setup. Wealthy, svelte widow Nancy Gutman is convinced that S.F.'s psychotic, serial ``April Fool Killer'' is her son Vincent, supposedly killed in Vietnam back in `72. So St. John, with sidekicks Mickey (sexy, aloof) and the Chief (towering Seminole), goes looking for Vincent—tracking down his ex-wife and his daughter, who's a hooker at the ``Seven Veils Ranch'' in Reno. Babula's promising idea, however, soon falls apart—as corpses pile up (Vincent's, the daughter's) and a tangle of tedious subplots is dragged in: a fanatical general's secret army of MIA Vietnam vets; a TV evangelist's adulterous wife; an extortion scheme against Vietnamese merchants. And the result is another overknotted, undertextured serving of shamus nonsense—breezily harmless but finally wearisome, with St. John's smirky narration and lame running gags about his pursuit (including a tennis duel) of the luscious Mickey.