An undercover cop and a mole in the police attempt to identify each other while infiltrating an Irish gang in South Boston.
Director
Martin Scorsese
Writers
Screenplay
William Monahan
Based on Infernal Affairs
Alan Mak
Felix Chong
Cast
Leonardo DiCaprio as Trooper William "Billy" Costigan Jr.
Matt Damon as Staff Sergeant Colin Sullivan
Jack Nicholson as Frank Costello
Mark Wahlberg as Staff Sergeant Sean Dignam
Martin Sheen as Captain Oliver "Charlie" Queenan
Ray Winstone as Arnold "Frenchie" French
Vera Farmiga as Dr. Madolyn Madden
Alec Baldwin as Captain George Ellerby
Anthony Anderson as Trooper Brown
Kevin Corrigan as Sean Costigan
James Badge Dale as Trooper Barrigan
David O'Hara as Patrick "Fitzy" Fitzgibbons
Mark Rolston as Tim Delahunt
Robert Wahlberg as FBI Special Agent Frank Lazio
Kristen Dalton as Gwen
Amanda Lynch as Carmen
Shay Duffin as Phil
