A serial killer claims to have clues about the murder of another prisoner; Frankie Jr. prepares to take the detectives exam.

A bride is killed right before she walks down the aisle, and Jane and Maura must figure out if the groom’s ex-girlfriend is a suspect, or if there’s a deeper connection to the bride’s European roots. On the homefront, Jane has a new neighbor who captures the attention of Angela, Frankie and Frost.

Frankie Jr. is brought in to help with a gruesome murder case involving a youth hockey league. Frustrated with Hope, Cailin asks to stay with Maura. But Maura quickly learns that living with a teenager requires skills she does not have.

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.