After taking a bullet in the Season Finale during a siege of the precinct, Jane Rizzoli is honored as a hero at a public event. The celebration is short-lived, however, when disaster strikes. The ensuing case reunites Jane with an old high-school flame, Sgt. Major Casey Jones, who may be just the person she needs to heal her emotional scars.

Jane attends her high school reunion and brings Maura along for the ride, but the fun is cut short when one of her old classmates turns up dead on the football field. Jane must focus on the past when she realizes everyone in her class is a potential suspect. Meanwhile, Korsak gets a visit from ex-wife Melody Patterson (guest star Lolita Davidovich), who hopes he’ll invest in her new business. Chris Vance returns as Sgt. Major Charles “Casey” Jones, an old flame of Jane’s, and Matthew Del Negro guest-stars as Angela’s car mechanic, Giovanni, who once had eyes for Maura.

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.

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.

Dr. Hope Martin returns to ask Maura for a life-altering favor. Jane worries about the impending spinal surgery for Lt. Col. Casey Jones (guest star Chris Vance), and Tommy shows off baby T.J. But all gets shoved to the side when a building collapses, trapping loved ones inside.

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.

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.

The squad rushes to solve a violent homicide case muddied by conflicting evidence. Maura is burdened with the major decision of whether to take in her recently paroled grandfather. Meanwhile, Jane and Casey are forced to decide between their careers and their romantic relationship.

A kidnapper dressed as a clown re-emerges after 20 years; Jane's relationship with Casey grows more serious; Maura inadvertently gets in the middle of another relationship.