Fenno is the pseudonym ``for a long-established literary figure''--and the publisher is trying hard to generate excitement and suspense about who the author really is (to be revealed with hoopla in September). Maybe that's because the book itself, though dubbed a ``mystery'' and written with much style and wit, offers a thin, vaguely familiar story and no suspense whatsoever. British physicist Erich Sturmer, 66, on vacation in the Bavarian Alps with beautiful, 40-ish wife Chandra (an Indian-born theologian), disappears while recklessly skiing--and is presumed dead in an avalanche, his body unrecoverable until the weather gets warmer. Chandra wonders whether Erich's accident was in some way connected to beefy local lad Siggy Geist--a sexual athlete and primitive mathematical prodigy who'd been sharing Chandra's bed (with Erich's acquiescence) and inspiring Erich's new theories about time-and-space. Then, back in England, the focus shifts largely to narrator John Peake, a middle-aged bachelor attorney and the Sturmers' best friend--who has always sort-of-loved Chandra but marries someone else when the widow turns out to be pregnant with twins (by Erich? by Siggy?). And the book's second half follows Peake as he responds to proliferating rumors that Erich isn't really dead at all--traveling to Bavaria (where Chandra's father, a Nobel-winning biochemist, falsely identifies a thawed-out corpse) and to Monaco (where a look-alike for Erich has been sighted at the casinos). Fenno, a writer in the wry, archly intelligent, very British manner of N.S. Wilson, fills out this scenario with ironic chat about reincarnation, academia, infidelity, and Heidegger--and with a few vivid supporting characters. But Peake remains an uninvolving hero, more literary than lifelike, and the predictable denouement manages to be limp and overly melodramatic at the same time. In sum: sporadically intriguing, highly civilized, yet ultimately rather boring--no matter who wrote it.