Spangled with naughty bits, Yulsman's first novel is a busy, brassy, fragmented reworking of that ever-popular sci-fi query: what could happen when a time traveler elects to change history? (Cf. Jack Finney et al.) In this case a dying octogenarian, given her second chance, returns to youth and decides to rub out Adolf Hitler--accomplished in her parallel universe, in 1913, in a Vienna cafe. The reader, however, only learns about this parallel-universe history slowly and obliquely--since most of the narrative takes place in this what-if? world circa 1983, with flashbacks and universe-jumps filling in the picture in teasing bits and pieces. Everything's different in this no-Hitler 20th-century, of course, as Yulsman's interpolated news briefs make cutely clear. And his quasi-1983 heroine is Lesley Morning, first seen leaving her L.A. husband and taking a ""magmtrain"" (an hour coast-to-coast), coming to N.Y. to tell her troubles to Mother. Then, intrigued by Mother's hints about paternal grandma Elleander (was she a murderer?), Lesley sails to explore her roots in England. . . only to find that her father has just died there. Furthermore, father Harry has left Lesley--and nice gay lawyer Freddy--a bushel of mysteries to decipher, including two strange documents: a completely baffling ""Time-Life History of the Second World War"" (what's that); and the pornographic memoir of a 1910 London gentleman called ""B,"" describing his bizarre encounter in a cab with a handsome, non-mercenary prostitute. What's going on here? So wonders Lesley--whose researches lead her to: attractive Paul Bauer, Canadian-raised information officer at the German Embassy; his uncle, Field Marshal Rudolph von Seydlitz, a fascistic type for whom Paul has no affinity; plus a clutch of cinema and photo pros who authenticate those photos of what never took place. (All this while Lesley and Paul dine to the music of the aging Glenn Miller, read the news of Ted Williams' 715th home run, etc.) Then Lesley discovers that her grandmother's grave held two bodies, one old, one young with a bullet hole in the head--both the same person! Finally, then, grandma Elleander Morning's lives and guises are unrolled: the gorgeous, successful brothel madam; confidante of H. G. Wells; wife to Bertram (""B"") and mother of Harry (lost in WW 11). And, back in the neo-present with Lesley, certain Germans are thrilled with the Time-Life story; and other enterprising persons, knowing what they know, are set to nip another Third Reich in the bud. For those with a taste for ingenious hypothetical concoctions: a bright, showy puzzle--more hectic than genuinely dazzling, perhaps, but tricky and bouncy and strange.