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 the responsibilities of MI6 in relation to the Security Service (MI5); MI6's security responsibilities in Europe and other foreign territories; programmes for Brook's visit to review MI6; problems maintaining the secrecy of the organisation; and a lengthy written response by Sir William Strang to the Brook report.