When a woman finds her husband has been murdered, the ensuing investigation reveals that the victim may have been living a double life.
The squad works overtime hunting down a serial killer sniper. Maura befriends a witness to the crime, who happens to suffer from a mental condition that has him believing he is a wolf.
After a man is found bludgeoned to death on the side of the road, Jane and the squad team up with another detective who believes he is hunting the same roadside killer. Meanwhile, Maura discovers she has had her identity stolen and recruits Angela to help track down the culprit.
The squad is forced to join forces with an over-eager private investigator when a successful clothing designer is found poisoned and his wife reported missing. Jane notices Angela is spending too much money and asks Maura to teach her mom how to handle her finances.
When a severed human foot washes up on shore, the squad is called in to identify the victim and track down the murderer as more body parts are found. After an unsuccessful job hunt, Angela finds she enjoys helping out Korsak at the Dirty Robber.
After Jane jumps from a bridge to save a prosecutor suspected of his murdering his mistress, Maura is terrified that she has lost her best friend. The squad must now renew the search to find the real killer. Meanwhile, Angela enlists Frankie's help as she applies to new jobs.
A notable county prosecutor is arrested for murder; when Angela hears that Maura is planning to meet Jack's daughter, she sets out to educate Maura about the interests of children today.
Jane and Maura find a man who died in a bathtub full of ice; while trying to stay cool during a heatwave, Angela discovers a spicy tea that brings unexpected romantic consequences.
The team helps Korsak investigate a cold case; Jane refuses to believe that she is not ready to go back on duty.
The team's skills are tested when the mummified remains of a woman are found; Jane tries to recover from a devastating loss.
The team tries to find a witness to the contract killing of a woman outside of a nightclub; Jane puts herself in the line of fire.
Jane and Maura are brought into the world of Keltic writings by the murder of a rare bookseller; Angela's relationship with Cavanaugh changes and Maura prepares Jane to meet her new man.
While Maura is away at a convention, Jane needs Susie's help to solve a murder; Korsak is forced to deal with painful unfinished business.
The team investigates the murder of a wealthy woman with terminal cancer; Maura meets a man while teaching a class.
A man is found murdered inside his doomsday fallout shelter; Jane finds out that Korsak is considering retirement; Frankie keeps a secret.
A killer uses online ads to find victims; Jane discovers that it will be difficult to keep her pregnancy quiet.
A woman walks into the station and confesses to killing someone; the team tries to unravel a bizarre case while dealing with the loss of a colleague.
Jane works to solve the murder of a jogger; Jane tries to hide her pregnancy from her mother; Maura and Frankie face the aftermath of their kiss.