I also loved the movie. This is the way I think Dignam(Walberg) knew it was Sullivan (Damon) in the end. Costigan(Leo) gave Sullivan's wife a envelope with info in it. Told here to open it if he died or if he told here to. It probably had something about contacting Dignam and giving him who the rat was and everything. Now she probably didnt know he would go out and kill Sullivan, but thats what happened. I personally liked how just about everyone died in the end. Not many movies like that. My grandma was dissapointed that the "good" guy didnt get the girl and win in the end, but I liked how it ended. :happy0144: One of the better movies that I've seen recently.EDIT:Also, Brad Pitt was signed on for this movie, but when Babel came up, he did that enstead. He's actaully one of the producers of the movie. What role would you of wanted Pitt to play if he'd been more envolved? I think he could of been a real good Dignam or Sullivan. Not saying Walberg or Damon werent good, just saying Pitt would of gave an equal or better performance. I just cant see Pitt playing Costigan.