In Dark Harbor, Maine, Stone Barrington discovers a picturesque town where the shocking deaths of three people have cast a long shadow over this island haven - a locale as mysterious as it is exclusive. Stone Barrington hasn't heard from his cousin, Dick Stone, in years - though he has fond memories of a teenage summer spent at his house in Maine. But then the CIA's Lance Cabot interrupts an otherwise pleasant meal at Elaine's with news of Dick's death - apparently by his own hand. It seems that Dick Stone, a quiet family man who doubled as a CIA agent, methodically executed his wife, daughter, and then himself - or did he? With the help of his ex-partner, Dino, and his friend Holly Barker, Stone must piece together the elusive facts of his cousin's life and death as a CIA operative.