A file of correspondence and memoranda relating to a report by Sir Norman Brook into the state of the secret intelligence and security services, and in particular the Secret Intelligence Service (MI6). Amongst the topics discussed in this file are expenditure by the secret services between 1946 and 1951, broken down by financial year; the services received for free from other government departments; the cost of the Admiralty intelligence section; and the importance, costs and personnel requirements of the collection of signals intelligence at the Government Communications Headquarters (GCHQ).