Thirteen died in Londonderry on Sunday, 30 January 1972, and this dramatic reconstruction, based on eyewitness accounts, uses a 24-hour timeframe to piece together the tragic course of events. Confrontation looms as local Protestant MP Ivan Cooper (Nesbitt) decides to press ahead with a banned march against internment without trial. He determinedly distances himself from the IRA, but the British army decides to target the occasion to take out the ringleaders. With a prowling handheld camera and relentless cutting, the film builds almost unbearable tension (comparisons with The Battle of Algiers are not inappropriate) before erupting into carnage. Although its assertion that the Paras fired first remains contentious, it's still a persuasive picture of fateful circumstances falling into place, carefully portraying the differences of attitude among the army personnel, some of whom realise the iniquity of their actions, with Nesbitt's stand-out performance putting an anguished human face on the day ideals died.