Ken and Harry call in on the spur of the moment to check Don Jakes, the security guard that they have employed at a safety deposit company, Unicorn Deposit Ltd. While searching for him, they walk into the vault. The door swings shut and an unknown person locks it behind them, trapping them inside. Ken and Harry see that the vault has been ransacked and that the cable for the security camera has been cut. They realise that they will probably be trapped all weekend. They think that Don might have been attacked, which is why he can't rescue them. Don leaves the vault and meets his Scottish girlfriend, Billie. They have stolen the contents of the vault and are planning to run away together to Argentina. Ken had arranged to meet Laura, who is getting obscene phone calls at home. When he doesn't turn up and she can't contact either him or Harry, she gets very worried. She and Rocky start to investigate. Don's wife, Jeanette, becomes suspicious when she sees Don with Billie, who is her hairdresser. She tips off the police who arrest Don and Billie on the way to the airport and recover some of the stolen property. Although Don Jakes appeared to be completely reputable, with good army references, Ken and Harry are beginning to suspect that he could be guilty. Ken suggests looking for food in the safety deposit boxes. They find some tins of caviare and some bottle of vodka. Harry has a sudden attack of conscience and thinks that it would be stealing to eat the caviare, but Ken persuades him that they must eat and drink to survive. They gorge themselves and consume large amounts of vodka. Before long they are both very drunk and start rambling on about life in the fire brigade and their ambitions for the future. Ted Hatchard, Ken's policeman friend, tips off Laura and Rocky that Don has a criminal record. They go back to Unicorn, together with the manager who eventually manages to get the vault door open. Ken and Harry are lying drunk and incapable on the floor with sheepish grins on their faces!moreless