
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
No 23: Mr Davis

Nova Pilbeam
Beppie Leemans

Reginald Tate
Maj. Richards

John Chandos
No 16

Stephen Murray
Mr. Barratt

Jack Hawkins
Brigade Major Harcourt

Geoffrey Hibbert
Pvt. John

Philip Friend
Lt. Cummins

Phyllis Stanley
Miss Clare

Mary Clare
Mrs. Webster

Basil Sydney
Naval captain

Joss Ambler
Mr Vemon

Brefni O'Rorke
Brigadier Blunt
Alexander Field
Pvt. Durnford

David Hutcheson
Intelligence officer