lotte nell'ombra (1939)

a band of criminals takes over a valuable military secret (the formula of a new explosive) and, not being able to decipher the complex figures, kidnaps the inventor's collaborator. to induce the woman to reveal the secret, they let her witness the torture inflicted on her boyfriend, who was also kidnapped by criminals. after numerous and dramatic adventures, the young man manages to escape, frees the girl and evacuates the gang.