Howard Sills has been the sheriff of Putnam County, Ga., for the past 21 years. Before that, he was a detective who solved every murder case that came his way until someone killed Russell Dermond, 88, and his wife, Shirley, 87. The case weighs on him, as he can't explain how they wound up dead. He has no witnesses or suspects. He has no motive, DNA, fingerprints or even a crime scene. But perhaps the most disturbing question he has yet to answer: Where in the world is Russell Dermond's head?