Aftershock follows four groups of people in the minutes, hours and days after Wellington is struck by a magnitude 8.2 earthquake and subsequent tsunami. Buried office workers must pull together. Strangers, caught by the tsunami on a ruined motorway, put themselves in danger to save others. A mother must reunite her family. And, at the centre of the rescue operation, a controller is bunkered down at Wellington’s Emergency Management Office.

En avril 1980, un commando de 6 soldats iraniens du Khouzistan opposés à la République islamique fait irruption à l'Ambassade d'Iran de Londres et prend les personnes présentes en otage. Ils réclament la libération de 91 prisonners, mais le Président refuse. 6 jours plus tard, alors que la situation s'enlise, les SAS donnent l'assaut...