What’s more important: loyalty to one’s family or to a cause? That’s the conundrum for Collette McVeigh (Andrea Riseborough), an Irish Republican from Belfast who’s just been nicked by British intelligence for trying to plant a bomb in the London Underground. But she’s a single mom with a young son, so an MI5 agent named Mac (Clive Owen) tells her she can either cooperate and become an informant or go to jail for so long that her boy will grow up without her.
Collette lives with her mother (Brid Brennan) and two brothers, Gerry (Aidan Gillen) and Connor (Domhnall Gleeson), both of whom shoulder considerable responsibilities for the Irish Republican Army. There...