McMillan (The London Restoration) spins a gripping story of Cold War espionage as two British operatives in a marriage of convenience become immersed in a dangerous mission. In 1946, Simon Barrington, illegitimate son of the aristocratic Barringtons of Sussex, works in Vienna to uncover the secrets of the Eternity spy ring. Meanwhile, he pines for his wife, Lady Sophie Huntington-Villiers, a woman he's loved for years despite the strictly platonic terms of their marriage, which was engineered to save Simon's inheritance. Sophie is also in Vienna, using the code name Starling to hunt down rare antiques and artifacts for the highest bidder. After one of Sophie's contacts dies mysteriously, Sophie is contacted by a client seeking Mozart's death mask, an artifact that Sophie is not sure exists--and the search plunges her into danger. Simon fears for her safety when he learns of a double agent, leading him down an equally thorny path in his efforts to uncover the traitor. McMillan's vivid descriptions of a postwar Vienna add allure to the simmering, romantic mystery. Readers will be riveted from the very first page. Agent: William Jensen, William K Jensen Literary. (Mar.)