When Owen Gilroy sets out to help his adolescent grandson, Sam, come to terms with his sexuality, he is forced to examine his own life by exploring that of—and solving a mystery about—their ancestor, Hiram Milhouse, a leading 19th-century scientist. Owen's discoveries are triggered when he and his partner Brock buy an old house in Philadelphia which once was Hiram's. Owen is soon tested by an affair that threatens his household and nearly destroys his effort to help Sam. His journey into the past, like his struggle to guide, then rescue, his grandson, reveals much about the changing shape of gay life in America today. The story of Owen and Sam unfolds against the backdrop of 9/11, terrorism, creationism, the Iraq War, and human cloning. Hiram's 19th-century world features a runaway slave, Darwinism, the Civil War, religion, and Republicans. In the end, the secrets of the past will have a profound impact on the lives of Owen and Sam.