As London's offices close for the day, an invisible army of 250,000 people begin work, the focus of this beguiling documentary. Ecuadorian Ana juggles two cleaning jobs in Canary Wharf and the City, while qualified mechanic Tesfalem from Eritrea buffs up the Houses of Parliament. It's an alien life in which some long for recognition while others embrace anonymity. Producer Phil Rees ; Executive producer Fiona Stourton