Italian naval secret agents acquire a British codebook and the Italian counter-espionage agents start tracking enemy agents working undercover in Italy and providing false information.
Mara Lane
Eduardo Ciannelli
Giorgio Albertazzi
Paolo Stoppa
Hans Hinrich
Franco Barbaro
Aldo Saporetti
Corrado Annicelli
Franco Caruso
Adriana Danieli
Ugo Sasso