Frankie Jr. becomes involved with a murder case involving a youth hockey league. At odds with Hope, Cailin ask Maura if she can stay at her house but Maura soon discovers she is unprepared to deal with a teenager.
Jane's preoccupied with Lt. Martinez's favoritism for the drug unit rather than on the case at hand involving the hit and run of a popular high school teacher.
After spilling hot coffee on a stranger, Jane's day goes from bad to worse when a video of the incident goes viral. The team investigates a murder that involves a conspiracy theorist.
While TJ's christening is marred when a body is found in the church, Lydia's fiancé threatens to take custody of TJ which doesn't set well with Jane. Department budget cuts has everyone on edge.
Hope provides some insight for Maura as Paddy's murder trial begins. But when Maura and Jane figure out a secret about Paddy and Hope, she must decide which side she's on. Korsak talks about Cavanaugh's tragic past.
With the evidence piling up, Jane tires to both protect Maura and investigate when Maura's date turns up dead and Maura can't remember anything about their evening together.
Jane's annoyed when a former colleague returns as the new lieutenant of the drug unit. But her investigation into the murder of a journalism student forces her to deal with him. Maura investigates Hope when Cailin come to her with some information.
Family issues and politics take center stage after a community parade turns deadly. Maura struggles with her own family issues. Casey makes a surprise visit along with some shocking news.