- Billy is back in the Special Investigations unit with Queenan and Dignam. It looks like SIU wants Billy to become an undercover cop and infiltrate the organized crime ring in his old neighborhood of Southie.
- The big catch is that the cops can't conceal the fact that Billy was a police trainee. So they'll have to give him back his street cred by convicting him of a crime and sending him to jail. Then he'll eventually get out on probation and see a court-ordered psychiatrist to convince everyone he's a legit gangster.
- We finally roll opening credits with a montage of Billy in jail, while Colin Sullivan lives the sweet life as a Staff Sergeant.
- Next thing we know, we see Billy Costigan back out of jail and pulling off drug deals with his cousin in Southie. His cousin mentions the fact that they shouldn't be doing what they're doing so close to Frank Costello's turf.