An icy, detailed portrait of a traitor, and a precise meditation on the nature of belief and betrayal. Banville (Athena, 1995, etc.) tends to allow the shimmering intensity of his prose to overcome plot and character. This time out, though, he keeps matters moving along briskly and his prose, while still vigorous, firmly under control. Sir Victor Maskell, an elderly, much-honored art historian, is revealed in Parliament to have been a spy for the Soviets. Stripped of his knighthood, his various positions and honors, and dying of cancer, Maskell sits down to explain himself. The resulting memoir, ironic, full of lacerating self-knowledge and acidic portraits of his fellow traitors, provides both a lively portrait of art and intelligence circles in Britain from the 1920s to the '70s and a meditation on the forces that inspire treason. Victor is a suitably complex and tormented figure. (Banville, to his credit, is clearly not interested in making him a particularly sympathetic one.) He is a perpetual outsider: An Irish Protestant, far less self-assured than his elegant Cambridge classmates, ambiguous about his sexuality, and more interested in art history than in the contemporary world, he seems to embrace Marxism more to fit in than to assert some firm belief, and to become a traitor more to please his friends than to assert a cause. This is, of course, well-plowed ground: Maskell is in some ways decidedly similar to Anthony Blunt, the art historian/spy, and his circle equally recognizable. Still, Maskell's fierce intelligence, his unblinking consideration of his past, sets this book apart from most fictional explorations of the spy's mentality. There's another reason that Maskell is writing his memoirs: He hopes, by doing so, to uncover who it was that turned him in, and why. He does so, in a bitterly ironic and understated climax. A resonant reworking of a seemingly exhausted genre, and a subtle, sad, and deeply moving work.