Having broached the U.S. Bible Belt and a grim Yorkshire circa 1980 in previous works, director James Marsh’s commitment to eschewing the obvious in terms of treatment and subject matter has him here turn to the mid-‘90s endgame of the Troubles in Northern Ireland. His subject is Collette (Andrea Riseborough), a single mother facing a jail term unless she complies with MI5’s demands for her to operate as a Republican informant. Unable to give anything away to a family who have their own tragic reasons for joining the armed struggle, Riseborough manages the difficult task of conveying her bitterly divided loyalties to the audience. An Oscar-winner for his documentary Man on Wire, Marsh here is in fine form, handling the complexity of the situations, and the emotions they generate, with uncompromising severity in this tense, humane insight into the terror of a woman forced into informing on her own people.