| Director | Peter Yates |
|---|---|
| Budget | £395,338 |
A criminal gang uses a gas canister to knock out the occupant of a car and then bundles him into a stolen ambulance. There, the gang cuts free a briefcase full of jewellery. Shortly afterward, while the criminals change vehicles, they are spotted by the police. A high-speed chase develops, and the criminals get away.
Using the money from this job, crime boss Paul Clifton builds up a team to hit a Royal Mail train coming south from Glasgow. A meticulous plan is put in place, but there are obstacles: Jack, the driver of the getaway car in the jewellery theft, is identified in an identity parade and arrested but refuses to name accomplices to police; gang member Robinson must be broken out of prison; and Inspector George Langdon is hot on the trail of the jewel robbers and finds out through informers about plans for an even bigger heist.
The gang gathers to do the job and change the signals to stop the train and escape with the cash. In the morning, Langdon and the police investigate the crime scene and explore possible local hideouts, including a disused airbase in which the robbers are hiding in the basement, but are not found.
The cash is divided up and the getaway vehicles hidden at a scrapyard. The members wait in turn to take their share to Switzerland. However, the paid-off scrapyard man is arrested at an airport, is found with banknotes from the raid, and confesses. Police then arrest some of the gang as they retrieve cars at the scrapyard. That leads the police back to the airfield, where they arrest further gang members.
Clifton evades capture, places his cut of the money on a private plane, and is last seen disembarking at New York with a different identity.