A young mother (Michelle Williams) lives with her husband, Lenny, and son in a concrete tower block overlooking the home of journalist Jasper Black (Ewan McGregor). When Lenny is away on bomb disposal duties, she seeks solace in someone charming and sympathetic like Jasper. After meeting Jasper, tragedy strikes with a stadium ripped apart by massive explosions. Jasper leads the young mother to the twelve-year-old son of one of the suicide bombers, with everyone's fate hanging on the real truth behind the events of that Mayday.