On the season finale, a undercover cop is shot, execution style. The police chief orders all personnel to be on the streets working the case, leaving a skeleton crew at the station. Jane interviews a witness to the murders that can identify who it shot the cop. The cops former partner is also at the precinct. While interviewing the witness, the police station comes under siege and cops are being shot left and right. Jimmy is shot. Maura manages to hide and bare witness to them trying to find something in evidence. Korsac feels something if off and goes to the precinct. Maura is forced to do surgery on Jimmy who is running out of time. Maura tells Jane that they were looking for something in the evidence lockers. Jane remembers the pack of cigarette just as the man who killed the cop enters the morgue. The cops former partner shoots him dead and retrieves the package, revealing he was the one that ordered is partner to be executed. He takes Jane hostage, and in the final moments Jane is shot and the ex partner also with the same bullet, as shocked Maura and the rest of team watches her fall.
