Fifty Dead Men Walking

Based on Martin McGartland's shocking real life story, Martin is a young lad from west Belfast in the late 1980s who is recruited by the British Police to spy on the IRA. He works his way up the ranks as a volunteer for the IRA whilst feeding information to his British handler and saving lives in the process; until one day he is exposed, captured and tortured to within an inch of his life. He escaped dramatically by throwing himself from a tower block window and is still in hiding today.

Fifty Dead Men Walking is a 2008 crime thriller film written and directed by Kari Skogland. It is a loose adaptation of Martin McGartland's 1997 autobiography of the same name. It premiered in September 2008, and stars Jim Sturgess as Martin McGartland, an informant within the Provisional Irish Republican Army (IRA), and Ben Kingsley as Fergus, his British handler.

Source: Wikipedia