Previous outings for San Francisco shamus Amos McGuffin (Dead on the Stick, Fade Out) have offered a fairly agreeable blend of easy-going farce and hard-boiled sleuthing. This latest caper, however, is a rougher, far less palatable mix--with alternating stretches of humorless melodrama and strained silliness (with lots of cutesy allusions to The Maltese Falcon). McGuffin returns to S.F. from the Caribbean to find that his ex-wife and young daughter have disappeared. Could they have been abducted? So it seems. And all clues indicate that the kidnapper is McGuffin's bygone nemesis, gay Nazi war-criminal Otto Kroger, recently released from the Napa Hospital for the Criminally Insane (18 years after murdering McGuffin's mentor, p.i. Miles Dwindling). So the shamus seeks out Kruger's former lover, fat Klaus Vandenhof, who offers to help--if McGuffm recovers the priceless Faberge egg (Nazi booty) that Kruger apparently stole from Vandenhof way back when. But when McGuffin finds Kruger, the vicious old lunatic announces that it was Miles Dwindling who really stole the egg--and that finding this treasure is the only way for McGuffin to save his family. The next step, then, is to track down Dwindling's daughter--who's being chased by the KGB, who also want the egg . . .and so on, through chases and shootouts and corpses galore, to a truly irritating twisteroo-windup. Cartoon villains, incongruous dollops of maudlin sentiment, inanely implausible plotting: an unfunny, disappointing misfire.