A file of signals intelligence reports, messages, and correspondence issued by the Government Code and Cypher School and sent by the head ('C') of the Secret Intelligence Service (MI6) to the Prime Minister, Winston Churchill. This file includes the following reports: Naval Headlines; from the Bulgarian minister in Berne, on Allied relations and the German offensive, on January 12; and from the Persian consulate-general in New York, that the three-power meeting is probably to be in Tehran, on January 10.