While investigating her late parents' involvement with the Anglo Iranian Oil Company (BP), the filmmaker comes across the letters of a petroleum geologist in Iran in the 1930s who was later to embark on a search for the origins of civilisation. The Host sets out on its own exploration, to decipher signs from the fragmented images buried in the BP archive. This journey through the past interweaves a number of stories drawn from both personal memory and the records of an imperial history, which builds a picture of a 20th-century colonial encounter. The Host is a personal essay film about the stories we tell about ourselves and others, the facts and fictions we live by, and their consequences. Followed by a discussion with Miranda Pennell.