Lots of slogans such as "Be like Dad, Keep Mum" and "Keep it under your Hat" are visible on the walls in various scenes to reinforce the plot of this British wartime movie illustrating how gossipy talk can result in unknowingly giving valuable information to Nazi spies.
Mervyn Johns
Nova Pilbeam
Reginald Tate
John Chandos
Stephen Murray
Jack Hawkins
Geoffrey Hibbert
Philip Friend
Phyllis Stanley
Mary Clare
Basil Sydney
Joss Ambler
Brefni O'Rorke
Alexander Field
David Hutcheson
Torin Thatcher
Thora Hird
Frederick Leister
Charles Victor
Richard Norris
Guy Maas
Basil Radford
Naunton Wayne
Johnnie Schofield
Frank Allenby
Victor Beaumont
Mark Daly
Ian Fleming
Hal Gordon
James Knight
Charles Rolfe
Jack Sharp
George Street
Guy Verney
H Victor Weske
John Williams