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: that Kesselring's battle headquarters are at Derna on May 26; that the 8th Air Corps is to attack Sevastopol, on May 27; of operational orders for the German Air Force (GAF) on the Eastern Front for May 27; and a correction of an earlier report of Soviet use of gas, on May 25.