Ripley Under Water by Patricia Highsmith

Ripley Under Water is a psychological thriller by Patricia Highsmith, the last in her series of five books known as the "Ripliad".

Tom Ripley leads a life of luxury at his chateau in Villeperce. He passes his days gardening, practicing the piano, and enjoying the company of his lovely wife. Never mind the blood-stains in the basement. But now he has new neighbors: a vulgar and curious American couple who, Ripley fears, may discover his secrets.