When Leo Banks was a young man, he fell hard for a woman named Sarah. Yet when Banks joined the navy during the Vietnam War, Sarah left him to marry his best friend, Gerry Heyman. Heyman became a doctor and settled with Sarah in Mauvaisterre, Illinois, his childhood hometown near St. Louis. He and Sarah had two kids, and life was good, just what both believed that they had always wanted. After the navy, Banks found his way by freight train to Rozette, Montana. Against all apparent odds, he became a police officer, completed a career, and retired. Gerry and Sarah Heyman were long out of his life, until the day they passed through town while on a vacation trip to Glacier Park.

Would Banks, Heyman asks, be willing to come to Mauvaisterre and help him investigate a murder that happened nearly fifty years ago? Heyman is convinced that an innocent man, a man with diminished mental capacity, was wrongly convicted. Banks is not interested, but things change not long afterward, when he gets word from Sarah that Gerry is dead. She suspects murder and a connection to his interest in the old crime. This changes everything and Banks is soon entangled with murder, old and new, a rich man who knows no way but his own, and a lover whom he had long believed gone from his life forever.