Perched high on a volcanic crag overlooking the River Forth, Stirling has long been one of the most strategically important castles in Britain. Guarding the gateway to the Highlands, its battle-scarred walls have witnessed savagery and chivalry, intrigue, alchemy, adultery and murder. With the aid of location filming, aerial shots and dramatic reconstructions, Dan Jones examines the history of this stronghold and relates the stories of some of the powerful characters who have owned it over the centuries.