Mark and Jo operate a scam whereby she tempts attached men back to their flat, where Mark plays the jealous husband in order to blackmail the men. The couple argue; she doesn't want to go to the club that night, as she's afraid the police are on to them. Mark promises her that they'll leave London the next day if she goes and they make up.

A basement nightclub: a band plays and couples dance. Three young men enter: Tom, Roy and Glynn. Tom has to be persuaded to go in as he feels guilty about betraying his girlfriend. They sit down and are joined by three hostesses; when Jo also sits down, one of the hostesses leaves. Glynn tells the women that they are students out celebrating Tom having won a prize.

Back at the flat, a man with a limp, Kleinie, walks up the stairs. He enters, turns up the radio and goes into the bedroom where Mark is.

Jo and Tom leave the club and make their way to her flat; he is very drunk. Meanwhile, at the flat, Kleinie stabs Mark. Jo and Tom bump into Kleinie as he leaves. Jo is distressed to see him but all seems to be normal when she gets back. She undresses and tries to kiss Tom but he rejects her advances. The telephone rings; it's Kleinie, who asks Jo if she's looked in the bedroom, telling her there is some rubbish to dispose of in there. He warns her not to tell the police who did it. Jo finds Mark's body; Tom follows her and pulls the knife out. He goes to the phone to call the police but Jo stops him and threatens to tell them that he did it. She orders him to get his car and bury the body out in the country. He puts the body in the car and starts to drive, still drunk and confused. The police see him driving erratically and give chase so he dumps the car and runs. He loses them in a graveyard and climbs into a building, where he collapses.

Next morning, he is woken by music playing over a loudspeaker, and finds himself in a bread factory. He sneaks out and buys a newpaper in which he reads about the previous night's events. Elsewhere, Mary, Tom's fiancée, reads the same story; she and Roy discuss what happened. Tom comes in and Mary runs into her bedroom, upset that he had gone back to a strange woman's flat. But they soon make up. Glynn arrives and they try and piece together what happened.

Glynn and Roy go to Jo's flat to find her but she's left and the barman at the club won't tell them anything. After they leave, he rings Kleinie to warn him and Kleinie sends his minders to find Jo and Tom. A plain-clothes policeman follows Glynn and Roy, who then go to the flat of one of the other hostesses, Lucy. She doesn't know where Jo is but suggests St. Pancras station. As Glynn and Roy leave, Kleinie's minders arrive at Lucy's flat.

Tom, Roy, Glynn and Mary go to St Pancras, followed by the policeman. Roy finds Jo in the café and they confront her but she refuses to go to the police and tell them the truth. The police arrive and they all flee, but Tom and Jo are bundled into a car by Kleinie and his men. The police follow the car out to a deserted quarry, where it crashes. Jo and Tom run away, chased by Kleinie, who shoots at them. He kills Jo, but the police catch up with him and he throws down his gun.