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 even more blurry. What exactly was Sofia involved in? One thing is clear: the killer will do anything it takes to keep their secret safe. Meanwhile, Angela Rizzoli hasn't had a decent night's sleep in all the years since her daughter's become a homicide detective. Maybe the apple didn't fall too far from the tree. Nothing in her neighborhood gets by Angela-definitely not the strange neighbors who have just moved in across the street. In a sleepy town like Angela's, there is no such thing as coincidence, if only Jane would listen. Instead, she writes off Angela's concerns as the result of an overactive imagination. But Angela's convinced there's a real wolf in her vicinity, and her cries might now fall on deaf ears. As old sins cast long shadows, Jane and Maura will have to race to discover the truth before the darkness consumes them.