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: a coversheet note - SHARK, that U-boat cipher keys have been broken, from March 25-28; on North Africa: the German Air Force (GAF) in Tunis' 2nd evening report for March 30, describing the enemy as following up fast on the Southern Front; that the 21st Panzer Division has 24 serviceable tanks out of 94, on March 27; that Hitler orders the Hermann Goering Division to Tunis, on March 30; and GAF Tunis' final evening report for March 30.