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 all her neighbors, lies in her own home, brutally bludgeoned. But anything can happen behind closed doors, and Sofia seemed to have plenty of secrets in her last days, making covert phone calls to old contacts and traceless burner phones. When a connection is made between Sofia and the victim of a hit-and-run months earlier, the case grows only blurrier.