"From the New York Times bestselling author of The Winter Sister comes a new work of psychological horror about a therapist who returns to the old family home after her sister drowns in its swimming pool, where she discovers that it has something sinister lurking beneath its surface"--,Provided by publisher.

When social worker Jax receives nine missed calls from her older sister, she assumes that Lexie is having another series of episodes. Manic and increasingly out of touch with reality, Lexie has pushed Jax away for over a year. The next day Lexie is dead: drowned in the pool at their grandmother's estate. When Jax arrives at the house she learns Lexie was researching the history of their family and the property. In 1929, thirty-seven-year-old newlywed Ethel Monroe hopes desperately for a baby. On a trip to Vermont with her husband, Ethel learns that the water in a natural spring at the modern hotel is rumored to grant wishes. She doesn't learn that the spring takes in equal measure to what it gives.... -- adapted from jacket