'You will live to regret this!' is Clara Brown's opinion when her headstrong daughter Fifi secretly marries Dan Reynolds, a handsome but itinerant bricklayer. Dan and Fifi move to London and a seedy flat in Dale Street, Kennington, and despite initial feelings of horror at her new surroundings, Fifi finds London and the freedom from her middle-class family background exhilarating. Insatiably inquisitive, Fifi is fascinated by her new neighbours and wants to know what goes on behind all those shabby front doors. Why is Yvette, the French dressmaker, such a hermit? And why doesn't widower Frank join his daughter and grandchildren in Australia? But most of all she is ghoulishly fascinated by the Muckles who live opposite in terrible squalor. When Fifi tries to help the Muckles' youngest child, who has been physically abused by her father, she unwittingly unleashes a chain of events that will bring not only heartache to her and Dan, but terrible danger to all the inhabitants of Dale Street . . .