A Cabinet minister is gunned down outside his home in London by a member of the Provisional IRA. Security protocols come into immediate effect, but the assassin evades them and manages to get back to Belfast unscathed. The military send Captain Harry Brown (Ray Lonnen) - a soldier who specialises in deep cover work in hostile situations - into the Falls Road area of Belfast, a place notorious for civil unrest. His mission: to infiltrate himself into the local population, hunt down the assassin and kill him on his own territory - proving to the IRA that they are not safe, even in their 'own back yard'. It is a terrifying game of cat and mouse, taking place in a civilian occupied war zone, where one mistake means certain death.