Detective Jane Rizzoli and medical examiner Maura Isles investigate the grisly murder of a wealthy couple. The M.O. matches the work of a serial killer known as the Surgeon, who once nearly murdered Jane. Now that the Surgeon is behind bars, it seems one of his protégés is picking up where he left off.
A member of a Boston "Brahmin" family is the victim of an apparent sailing accident. Maura's close family connection and Jane's resentment over the family's display of wealth causes friction between the two which affects the investigation. Angela tries selling a health drink.
Killers of an undercover narcotics cop target Boston homicide headquarters putting Jane, Maura and Frankie Jr. in a fight for their lives. Meanwhile, Angela and Frank eagerly await the return of their son, Tommy, who's being released from prison.