Littell (The Defection of A. J. Lewinter, The October Circle) continues to write U.S./Russia thrillers with a texture and tone that transcend the genre; but, as structured here, the plot of this new spy puzzle is simply too thin and see-through to support the three-dimensional approach. A Soviet courier, on his way to Cairo via Greece, has defected--complete with a pouch containing a slew of classified documents. The question to be answered by Stone of Task Force 753 (the ""elite private intelligence arm of the Chairman of the Joint Chiefs""): is this a genuine defection, or a Russian plot to foist some phony classified info on the U.S.? As Stone painstakingly, gently debriefs the defector (""It will end when we know more about you than God""), it becomes apparent that this courier, a middle-aged loser named Kulakov, certainly believes he is a genuine defector--but Stone suspects that Kulakov's desperate defection may have been psychologically orchestrated by the Soviets. So off goes wry, dour Stone to Russia--deeply incognito--to pose as a KGB agent, fall in love with a Moscow prostitute/contact, and find out the truth about all those domestic and career misfortunes that led Kulakov to defect; it turns out that poor Kulakov has indeed been ruthlessly manipulated by a military/intelligence faction. All of this is cleverly and gracefully put together, textured with such characters as ""Morning Stalin""--a former Stalin stand-in whom Stone coaxes out of retirement for one final, look-alike performance. But much of this detail work merely seems obtrusive, because Stone's course is so predictable, with no real revelations anywhere along the line. So: superb dialogue, glorious nuances, and whimsically faceted surfaces--which will be more than enough for some sophisticated suspense readers, but not quite enough for the many who'll notice that something's awry in the way that Littell has set up his serviceable but uninspired puzzle.