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: from the Japanese ambassador in Berlin, on new German weapons, on December 5, with an appreciation by Dr Jones; and from the Japanese naval attaché in Berlin, a complementary report on an inspection of new German weapons, on December 6.