A psychopathic killer murders three girls before police catch him.

Lorna Blake, (Ursula Jeans) is a widow with two daughters. She augments her slender income by using her children to extort money - visiting the houses of the rich to tell a pathetic story and beg for help. And Lorna makes a rich capture when Sir Halmar Bernard, (Cecil Parker), proposes to her. She tells him that she has only one daughter, Molly (Jill Freud, credited as Jill Raymond). When her other daughter, Jay (Jean Simmons), is arrested for forging a cheque, she refuses to help her.