S01E05 - The_Third_Floor_Flat

Four young people, two women and two men, are returning after a night out to the home of one of the women – Patricia Garnett. She is annoyed as she cannot find the key to her flat on the fourth floor of her apartment block in her handbag. The porter doesn't have a spare key, nor is there a fire escape, but the suggestion is made that the two men, Donovan Bailey and Jimmy Faulkener, make their way up through the coal lift and let the women in.