Boston homicide detective Jane Rizzoli and medical examiner Maura Isles are newly plagued by what seems like a completely senseless murder. Sofia Suarez, a widow and nurse who was universally liked by her neighbors, lies bludgeoned to death in her own home. But anything can happen behind closed doors, and Sofia seemed to have plenty of secrets in her last days, making covert phone calls to traceless burner phones. When Jane finally makes a connection between Sofia and the victim of a hit-and-run from months earlier, the case only grows more blurry. What exactly was Sofia involved in? One thing is clear: The killer will do anything it takes to keep their secret safe.