As the Boston Homicide detectives solve a murder, they each think of ways to say goodbye to Detective Barry Frost.

A killer is using online ads to find the perfect candidate for murder: men no one will notice are missing. Meanwhile, Jane discovers that keeping her pregnancy quiet will be a tough assignment.

A man is found dead inside his doomsday shelter. Maura determines he was suffocated by gas pumped into the shelter. Jane becomes distracted when she thinks Korsak is going to retire. Frankie has a secret.

The murder of a rare bookseller brings Jane and Maura into the world of Keltic writings and coded confessions, just as Maura is preparing Jane to meet her new man. Angela's relationship with Cavanaugh changes pace.

A woman is killed with a silencer outside a nightclub. First suspect is the husband who checked into a hotel, but he is found dead. A young witness to the suspected contract killing of the woman must be found and protected.

Mummified remains of a woman put the team's investigative skills to the test. Jane works from her hospital room as she - with the support of Maura and her family - seeks to recover from a devastating loss.

The team helps Korsak investigate an old case that has gone very, very cold. Jane refuses to believe that she's not ready to go back on duty and takes some untraditional steps to stay involved.

In the middle of a heat wave, Jane and Maura find a man who died suspiciously in a bathtub full of ice. In trying to stay cool, Angela discovers a spicy tea that seems to be working, but it has unexpected romantic consequences.

The squad works overtime hunting down a serial killer sniper. Maura befriends a man who is a witness to the crime, who happens to suffer from a mental condition that has him believing he is a wolf.

When a woman finds her husband has been murdered, the ensuing investigation reveals that the victim may have been living a double life.