Frank Costello (Jack Nicholson)’s Timeline and Summary
- We meet Frank in the opening scene of the movie, where he tells us that the only way to get ahead in America is to take whatever you want and stomp on whoever gets in your way.
- Frank builds himself a huge criminal organization and also makes friends with a young kid named Colin Sullivan. He helps Colin out with some groceries and starts mentoring the kid. When Colin grows up, he enters the police force and becomes a rat for Costello.
- One day, Frank takes notice of a young man named Billy Costigan who has returned to the Southie neighborhood after spending years away. Frank is interested in him because Billy's Uncle Jackie used to be one of his best criminal partners.
- Frank hears about Billy beating up a couple of mafia guys and he knows that the mafia guys will come back with some thugs to kill Billy. So he finds Billy and meets with him.
- Frank starts things off by interrogating Billy and telling him not to do anything criminal on his turf. Then he starts beating on Billy's injured arm and asking him if he's a cop, since Frank knows Billy was in the police academy.
- Frank brings Billy in to do some small jobs at first. But it isn't long before Billy is a full member of his gang.
- Eventually, Frank finds out from Colin Sullivan that he has a rat somewhere in his gang. He goes on a bit of a rampage trying to figure out who it is, but to no success.
- Frank sells some phony microprocessors to the Chinese and continues on with his usual criminal life. He also tells Colin Sullivan that if he (Colin) doesn't find the rat soon, Colin is going to be the one to pay for it.
- Eventually, Frank sits down with Billy and confronts him directly about being the rat in his organization. Billy threatens to kill Frank if he gets in his face again, and the gamble pays off, because Frank drops the subject and starts thinking about other stuff.
- Frank eventually loses his mind over his inability to find the rat in his gang. He gets so bold that he goes to one of his own drug deals and ends up getting surrounded by police.
- During the police raid, Costello finds himself alone with Colin and tries to shoot him. But Colin shoots and kills him first.