Three young criminals hold up a supermarket, and the youngest of the trio, Jimmy King, panics and shoots the manager. However, there is a witness, 'The Dodger', the object of a nagging wife who sees his opportunity to get some money and escape when King's accomplices get rid of him by throwing him from their getaway car outside the Railway Museum in Williamstown. The final showdown between the three criminals and the Homicide team takes place amongst the trains in the museum.