The official verdict on poet/publisher Richard Forsythe and his latest amoureuse, Sabine von Stuben, is that their deaths were the result of a suicide pact in their bolted Paris hotel room. But Richard's mother back in the States doesn't believe the official verdict--she's especially suspicious of the shooting of the hotel desk clerk soon afterward--and she hires the Pinkerton Agency to find out the truth. The Pinkertons, who don't do things by halves, send two operatives, experienced investigator Phil Beaumont, who'll read through police transcripts and question the witnesses, and novice Jane Turner, who'll travel incognito as nanny to Richard's cousins; but the company doesn't tell either one about the other. Since Phil and Jane have already met under other circumstances (Escapade, 1995), various complications ensue. The lazy if high-spirited detective work, however, is constantly upstaged by the cast of dragonish suspects--from Richard's man-eating widow to Sabine's former lover to an Agatha Christie look-alike who's been funneling donations to the infant Nazis--and a nonstop parade of period cameos that include Ernest (""call me Ernie"") Hemingway (a skirt, chasing poseur), Gertrude Stein (olympian in her vanity), James Joyce, Erik Satie, Juan Gris, Pablo Picasso, Kay Boyle, Robert McAlmon, and some terrific French meals. A decorative, dizzying trifle--the locked-room murder is solved with insulting casualness--that's chock-full of the stuff that made the Twenties roar.