A professor teaching at a correspondence school discovers that a Nazi agent is trying to prevent a trade treaty being signed between England and South America.
Prof. Davis
Bobby Jessop
Costello
Crabtree
Joyce
Prof. Davys
Innsbach
Sir John
Onslowe
Male Nurse
Station Master
Ticket Collector
Sister at Nursing Home
B.B.C. Producer
Butcher's Boy
Train Passenger
Mrs. Webster
Ministry Receptionist
Nurse
Porter
Director
Screenplay
Producer