Jane and Maura investigate the mysterious death of a young boy whose family is from Cape Verde. It appears at first that he may have died during an attempted exorcism, and it may take a message from beyond the grave for Jane to pinpoint exactly what happened. Jane is distracted from the case when her mother sets her up on a surprise date.

The eldest brother in a Boston “Brahmin” family (direct descendents of passengers on the Mayflower) is found in the harbor dead after an apparent sailing accident. But Maura’s close connection with the family and Jane’s resentment over the wealth they display threaten to derail their investigation. Angela, meanwhile, tries her hand at selling a Polynesian health drink.

Shortly after sailors invade the streets of Boston for Fleet Week, a young girl is found dead. Frost's father, a Navy Admiral, comes to town, causing tension with his son. And, Maura goes on a date with Angela's mechanic.

Jane and Maura investigate a family's background when a man is killed; Jane suspects that Maura is hiding something.