Alex, a radio-specialist sailor on leave, recovers from a drink-induced blackout with a large sum of money belonging to Edna Bartelli, a B-girl who invited him home to fix her radio. He tries to return the money with the reluctant aid of June Goffe, a sweet but oh-so-tired dance hall girl. They find Edna murdered. Not quite sure he didn't do it himself, Alex and June have four hours in the dead of night to find the real killer before his leave ends. Their quest brings them into contact with a sleazy kaleidoscope of minor characters as the clues get more and more tangled.