A widow attempts to fulfill her dead husband's last request—to enter his prize horse in the Derby—and plunges into a deadly world of blackmail, revenge, and murder Less than a year after arriving at his sprawling ancestral estate as his secretary, Isabel Cunningham marries the much-older Charles Schriber. But now Charles is gravely ill, and before he dies, he asks one last thing of his wife. Determined to honor her husband's deathbed wish, Isabel makes preparations to train the magnificent Silver Falcon to win the Epsom Derby. But someone doesn't want Isabel to succeed. When she almost drowns in an accident, suspicion immediately falls on Richard Schriber, Isabel's handsome, troubled stepson, who was estranged from his father for a decade and blames him for his mother's tragic suicide. As the Derby approaches and the violence escalates—a vicious attack on a stable boy is followed by two brutal murders—Isabel must confront a shattering truth about her deceased husband and the man who now ignites a dangerous desire in her. Is Richard the lover she can trust with her life? Or a homicidal maniac just waiting for the right moment to strike?