On October 1, 1991, Fran Gladden-Smith disappeared without a trace from her home in Princeton, New Jersey, and suspicion immediately turned to her new husband, John David Smith III. In a highly unusual move, the police allowed her family to be involved in the investigation as long as they didn't interfere with law enforcement. Over the next several years, Fran's sister Sherrie Gladden-Davis played a deadly game of cat-and-mouse, tracking Smith and his activities across the United States. She could go where police couldn't and she dedicated herself to helping authorities get the evidence they needed to unravel the mystery of her sister's disappearance. My Sister Is Missing is Sherrie Gladden-Davis's harrowing account of the search for her sister's killer, and the inspiring story of her extraordinary path to justice.