Based on the true story of Melbourne Johns, an aircraft factory foreman sent to France to prevent the Nazis getting hold of some vital equipment.

Clifford Evans
as Fred Carrick

Constance Cummings
as Anne Stafford

Tommy Trinder
as Tommy Hoskins

Gordon Jackson
as Alastair 'Jock' MacFarlan, 19th Fusillers

Robert Morley
as Mayor Coutare of Bivary

Owen Reynolds
as Collins, Burns & Fawcett Works Manager

Bill Blewitt
as Aircraft Spotter on Works Roof

Charles Victor
as Aircraft Spotter

John Williams
as 'English' Army Captain

Anthony Ainley
as Boy