Mary Harrington is a seventy-four-year-old widow who has kept her past a secret for forty-four years. She knows her life depends on her former employer never knowing where she lives, and she certainly doesn't want her son or granddaughter discovering what she did in her twenties. But, when two gang members try to mug her, she automatically reacts as she'd been trained, putting the two in the hospital. Although Mary denies being involved, Jack Rossini, the local police officer investigating the incident, believes she was. He's concerned that the gang will retaliate, and he can't understand Mary's reticence to press charges. When he tries to find out more about her, he discovers there's nothing prior to her moving to Rivershore, Michigan. In fact, his prying leads to an ominous warning to back off, and soon his life as well as Mary's is in danger.