Former literature professor Harriet "Harry" Wild is trying to adjust to retirement when she's injured in a mugging. While recovering at the home of her son, senior detective Charlie, Harry looks at his files and realizes his latest investigation bears similarities to an obscure Elizabethan play. After Charlie dismisses her insights, she decides to find the killer-with aid from a surprising source.

When a body is pulled out of the river near Harry's local pub, something about the dead man feels familiar to Harry. When she remembers how she knows him, she realizes she's stumbled onto the ultimate misdirect. Harry and Fergus go undercover, with the assistance of Harry's teenage granddaughter, Lola, to find the truth. Along the way, Harry starts to grow closer to Ray, Charlie's boss and mentor.