A body is discovered in the church at TJ's christening; Jane almost abuses her power to protect Tommy; Lydia's fiancé threatens to take custody of TJ; budget cuts cause tension at the department.

On the first day of Paddy’s murder trial, Maura gains insight into her father from Hope. Korsak opens up about Cavanaugh’s tragic past. And in an unexpected twist, Maura must decide which side she’s on when she and Jane unravel a shocking secret about Paddy and Hope that affects them all.

When Jane and Maura are asked to present the case of serial killer Charles Hoyt at a symposium for law enforcement, Jane worries that her greatest challenge will be facing bad memories. However, as she and Maura begin a simulation of investigating Hoyt’s murders, they soon come across a horrifying discovery. In a matter of moments, the team finds themselves drawn into a lethal game of cat and mouse with a new and terrifying serial killer.

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.

A musician is stabbed in a bar; the squad realizes that the stabbing victim had something to hide; Jane's father returns with shocking news.

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.