Joanna Trollope, . . Bloomsbury, $23.95 (320pp) ISBN 978-1-58234-400-3

As she has done adroitly in her previous novels (Marrying the Mistress , etc.), Trollope explores the unforeseen consequences of life-altering decisions, here telling the story of two adult adoptees who set out to find the mothers who gave them away. Nathalie and David were adopted as babies by a warm and loving couple, the Dexters, and they enjoyed happy childhoods. Their sibling bond continues to be unusually strong, and they still share a mutual pretense that being adopted gave them a psychic freedom impossible in a conventional family. Now David is married with three young children and a thriving gardening business. When Nathalie—living with artistic designer Steve and mother to five-year-old Polly—admits to herself that her lack of family history is an open wound, she convinces David that they both should trace down their biological mothers. Trollope's gifts for storytelling and sensitive characterization are again in evidence, as the siblings' search produces unsettling ramifications for their adoptive parents, their romantic partners and their children. The plot becomes somewhat formulaic when Trollope switches focus to the two birth mothers. One is a successful businesswoman who has put her past behind her, married and mothered two sons; the other, a passive waif, has lived all these years with constant heartache. After meeting their birth mothers for the first time, Nathalie and David each feel great relief and great sadness. Meanwhile, their relationships with their loved ones have changed, perhaps irrevocably. One of Trollope's strengths as a novelist is her empathy for her flawed characters and her recognition that conventional happy endings are not true to life. Although Nathalie and David unexpectedly open a Pandora's box of complications, the novel reaffirms the eternal truth that no one lives in a vacuum. 8-city author tour. (Apr. 24)