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 on Germany: of a complaint that German Air Force (GAF) air defence fighters are not coping with RAF tactics, on September 12; and on the Southern Russian Front: a German report that the 4th Panzer Army has broken into Stalingrad, on September 12.