The Man Who Wouldn't Talk plot
American scientist Frank Smith is on honeymoon in London with his new bride Eva Trent. The British authorities do not know that Frank and Eva are secret agents. Both are tasked with extracting classified military information from the Hungarian scientist, Professor Horvad. It has been agreed in advance that Smith will pass this information on to another person from the American secret service and must remain silent about their mission. However, this appointment proves to be a serious handicap for Smith when he finds Eve mortally wounded. Smith has no alibi because of the obligation of confidentiality imposed on him. Attorney Mary Randall must defend the gagged Smith in court.