In this gripping psychological thriller from the New York Times bestselling author of The Housekeeper, a dementia patient reveals a deadly secret—and one woman must decide whether to believe her.

Reeling from her husband’s death and best friend’s dementia diagnosis, seventy-six-year-old Linda Davidson is feeling lost and alone. Her beloved daughter Kleo and son-in-law Mick have moved into her house to keep her company, but the constant bickering quickly turns their presence into yet another worry on Linda’s long list. 

Eager to escape the tension at home, Linda goes to visit her friend at Legacy Place, a memory-care facility for the elderly, where she meets Jenny Cooper, a ninety-two-year-old dementia patient who makes a shocking confession: she kills people.  

Linda dismisses the so-called “secret” as the confusion of an ailing mind, but Jenny seems strangely lucid over the course of their visits as she recounts stories of her many victims—mostly men who'd hurt her. Then a fellow patient at Legacy Place dies. Everyone else sees the natural death of an old, sick man, but Linda can’t help but wonder: is there any chance Jenny’s telling the truth?