Counterspy Meets Scotland Yard plot
Spies steal classified information about missile control systems. Department head Professor Schuman finds out about this theft, but before he can report it to the Secret Service, he is murdered. Secret agent David Harding is informed about the murder case and he sets out to investigate. Schuman is said to have died of natural causes, but Harding still requests an autopsy. When Harding's employees go to Schuman's grave, they see someone digging there. It turns out to be Simon Langton, a Scotland Yard agent and also an acquaintance of Harding. Together they now try to solve the espionage case.