Costigan follows Costello into a porn theater, where Costello gives Sullivan an envelope containing personal information on his crew members. Costigan chases Sullivan through Chinatown. When it is over, neither man knows the other's identity. Sullivan has Queenan tailed to a meeting with Costigan on the roof of a building. Queenan orders Costigan to flee while he confronts Costello's men alone. The men then throw Queenan off the building to his death. When they exit, Costigan pretends he has come to join them. Television news reports that crew member Delahunt (Mark Rolston) has been a Boston Police Department undercover cop, but Costello believes it to be a lie probably designed to lull him into a sense of security. Dignam resigns rather than work with Sullivan, who he suspects is the mole after he is asked why he had Queenan followed.