Christopher Isherwood was an early-20th century writer whom the Doctor and Iris Wildthyme met in Berlin before he reached fame. At that time, he was living on the Nollendorfstrasse, with "that terrible floozy" who sang and kept trying to have sex him — "and poor Chris was only there in the city for the boys." The Doctor forgot this encounter by an adventure in his eighth incarnation, but remembered another account with the man in a picnic in a dusty valley with Bertrand Russell, Aldous Huxley and Greta Garbo. (PROSE: The Scarlet Empress)