When a warehouse fire kills a firefighter, Jane and Maura must investigate whether it was arson or an accident. But the investigation hits a snag when a hit-and-run leaves someone in the hospital. Guest star Billy Burke returns as FBI Agent Gabriel Dean, who hopes to rekindle his relationship with Jane. And guest star Jacqueline Bissett reprises her role as Maura’s mother, Constance Isles.

Tensions continue to mount between Jane and Maura, causing those close to them to be caught in the middle. But they must put aside their differences when they investigate the case of a college student who died in a tunnel. Meanwhile, Frankie Sr. returns with news that upsets Angela.

When Maura meets a new guy named Dennis in a very unusual way, he opens up a different side of her. And Jane is filled with mixed emotions after someone from her past returns.

Young female professionals dressed as dolls are turning up dead on the public transit system, and Jane and Maura must piece together the clues. Angela implements new ideas for the café. And Jane learns more about how Casey was injured.

A boy band star returns to his roots for a show and winds up murdered. Jane and Frankie, who grew up with the victim, work hard to solve the case. Meanwhile, Jane and Maura must decide if it’s time to tell Angela the truth about Lydia’s pregnancy just as Angela prepares to throw her a baby shower.

When a statue breaks open to reveal a dead woman inside, Jane and Maura must find the killer quickly as the body count begins to rise. Back at headquarters, a new homicide detective is named to the squad. Meanwhile, Dennis Rockmond returns to Boston after disappearing on Maura and tries to woo her back. Lydia goes into labor.

When a man having breakfast in the Division 1 Café dies from poisoning, Jane and the team must quickly find the source as Angela and the irascible Stanley both come under scrutiny. Meanwhile, Tommy wants proof that he’s the biological father of Lydia’s baby as she returns to take the baby back. And Detective Korsak is reunited with one of his ex-wives.

A famous young writer of memoirs is found dead in an apparent suicide, but Jane and Maura soon discover there’s more to the story. Meanwhile, Frost becomes obsessed with an old case involving a young African American student as his final appeal is denied. And Jane discovers Angela is involved in a secret romance.

The virtual world and the real world collide when a microbrewer is killed. Angela tries to move on from a failed romance by seeing someone new. And Jane and the team begin to mentor underprivileged teenagers, a move that ends in near disaster.

When a former college football player is stabbed inside a carwash during a fundraiser for his alma mater, Jane, Maura and the team must piece together clues to track down the killer. Meanwhile, Frost's mother visits Boston with some unexpected news. And Lt. Col. Casey Jones bumps into Jane and is forced to reveal some startling news of his own.

A community parade turns deadly in a case that brings family tensions and politics to the forefront. Maura, who is dealing with her own family issues, is not quite herself. And a surprise visit from Lt. Col. Casey Jones reveals some shocking news.

Jane is unhappy when a former colleague returns as the new lieutenant of the drug unit; a tip from Cailin causes Maura to investigate Hope.

Maura becomes the key suspect in a homicide case when Maura’s date turns up dead – and Maura can’t remember their evening together. As the shocking evidence against Maura piles up, Jane struggles between protecting her best friend and doing her job.

A popular high school teacher is killed in a hit and run that is clearly no accident. The squad works to solve the case, but Jane is preoccupied with Lt. Martinez’s apparent favoritism towards his own drug unit.

When a food truck chef dies suddenly, all signs point to poisoning; Tommy announces some big plans; Maura's birth mother tries to make amends with her daughter.

A senator's daughter is found murdered; Tommy begins to slip back into old habits; Jane reveals some shocking news.

A killer uses online ads to find victims; Jane discovers that it will be difficult to keep her pregnancy quiet.

A man is found murdered inside his doomsday fallout shelter; Jane finds out that Korsak is considering retirement; Frankie keeps a secret.

The team investigates the murder of a wealthy woman with terminal cancer; Maura meets a man while teaching a class.

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.

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.

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.

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.

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 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.

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

The team have to find out the identity of a killer of an unarmed man as they attempt to clear their detective's name.

Jane and Maura are called to the BCU "Body Farm" -- an academic research facility dedicated to the study of human decomposition -- when a murder victim is found buried in a shallow grave among the research corpses. Angela also has secrets she is keeping buried from Jane.

The murder of a notorious thief sends Jane and Maura into the world of art heists and forgery and forces Jane to tango with an F.B.I. Agent who has a keen interest in her case. There's also a new man in Angela's life.

The murder of a crime tech sends shockwaves throughout the team. When suspicions arise that the tech had tampered with evidence for BPD cases, Maura is suspended from her position. Jane is determined to catch the killer and clear the department so Maura can be reinstated.

When Maura is abducted, nothing will stand in the way of Jane and the team bringing her home. Far away, Maura discovers a conspiracy that is bigger than just her kidnapping, with Jane as its ultimate target.