Ring of Spies

Ring of Spies is a 1964 British spy film based on the real-life case of the Portland Spy Ring. A dissatisfied Navy clerk begins handling secret documents when he is approached by secret Czech intelligence to hand over documents to them. Although he is being black-mailed, he agrees to do so while also being paid for the information. He begins an affair with the secretary who also has access to greater secret documents. Together, the couple continue to procure information for Czech intelligence while getting paid. Soon, the British government gets wind of their betrayal.