Wartime tale of a group of British scientists efforts to develop the first radar system. They did it just in time for it to be used in the Battle of Britain against the might of the Nazi Luftwaffe. Without it the little island could well have been overrun.

• Two Cities Films
• General Film Distributors
• Ralph Richardson
• Raymond Huntley
• John Laurie
• Ernest Jay
• David Tomlinson
• Finlay Currie
• Norman Webb
• Michael Hordern