Gardiner's subtly powerful writing deserves a wider audience, but his latest book fails to live up to his earlier achievements. While In the Heart of the Whole World and the well-received Somewhere in France were crisply written explorations of characters haunted by their obsessions, his fifth novel, about mixed-race twins growing up in an orphanage in the 1920s and '30s, has fewer flashes of grace. At age 10, Rebecca and Linda arrive at the Drayton Orphanage outside Philadelphia. With their odd beauty (faintly olive skin, hair "blond as a corn tassel") and troubling bond ("Sometimes I can't remember which one of us is me," one says), they quickly cast a spell over orphanage director Eula Keiland. The twins also attract the attention of Otto Rank (real-life psychoanalyst, a disciple and later critic of Freud), one of the novel's several historical figures. Otto believes that everyone has an internalized double, but in the twins' case, "nature has provided the double" and there is "no need for the subconscious to produce another." He's also certain that the twins will destroy each other, as the mythical Greek twins Lezzor and Tripto did. The twins' race plays a crucial role, and all of these elements promise something spellbinding. But while sometimes effective, the novel disappoints. The twins endure two separate, harrowing journeys (one to California, the other to China), but Gardiner relates these events flatly, and the idea of the "double" is tirelessly debated—by Eula, Otto and their associates—giving the metaphor-heavy novel a static, leaden feel. Author tour. (Nov.)