West describes how the sparsely manned MO5G liaised and worked alongside the Police, Banks and Post Office Censors to protect the United Kingdom from traitors and enemy agents. Those agents are given biographies and a sympathetic telling of their story whether it ended in jail, deportation or execution. Strangely, although several MI5 officers are named and their personal actions recorded we get no such biographies for them
In 1921 MI5 commissioned a detailed review of the organisation's operations during the First World War. The survey, amounting to over 270,000 words in seven volumes, plus appendices, remained classified in MI5's registry and was only used in Whitehall to argue against budget cuts. MI5 in the Great War is a version of that top-secret history, concentrating on the main narrative of the Secret Intelligence Service's activities in the war, edited and brought up to date by bestselling writer and historian Nigel West.