Davidson (Murder Games, 1978) returns after a 16-year layoff -- during which he kept himself rather well informed -- to craft a plausible and sophisticated technothriller that, unfortunately, is also a lengthy Siberian travelogue. Cryptic messages smuggled out of a gulag-like research facility in Siberia issue a call for help from Professor Efraim Rogachev, who feels he must share his findings on genetics and optical relay systems with the world. With the global intelligence community's help, these notes finally find their way to Johnny Porter, a.k.a. Raven, a Canadian Indian whose resume includes an Oxford education, fluency in dozens of languages and dialects, and the ability to kick butt without leaving telltale footprints. Raven's well-documented mission eats up about two-thirds of the book and takes him from Japan, disguised as a Korean deckhand on-board a tramp steamer, to remotest Siberia, where he assumes the identity of a truck driver, to Rogachev's lab at Tcherni Vodi. Along the way are a few scrapes with seagoing toughs and a love interest in the shape of Dr. Tanya Komarov, who uncovers Raven's true identity and tags along to find Rogachev -- who, as it happens, is an old acquaintance of her deceased scientist father. Raven makes it to Tcherni Vodi, picks up the secret information, and shoves off for home with about half of Russia's border guard tailing him in a thrilling but all-too-brief pursuit across the top of the world. When the muse strikes him, Davidson creates forceful and immaculately written action, especially in the story's riveting climax and conclusion. But these passages comprise barely more than one-tenth of the story, with the rest mostly serving as a literary palate-cleanser. Beautifully presented, but less than filling -- a kind of gourmet thriller lite.