The Secret Service S01E05 - Last Train to Bufflers Halt

As part of an operation to seize £1 million in bank notes en route to London, the train loaded with the shipment is diverted to the disused Buffler's Halt Station. Assigned to protect the consignment, Unwin and Harding help to subdue the criminals responsible. However, back up the line, stationmaster Albert Hobson realises that he cannot stop the train, which is moving at 80 mph.