 However, Tangye later recorded that it had been ″written by the author as a cover to his assignment by MI5 as a secret agent in the Spanish War″ seeking information on German military involvement.There is independent evidence that he worked in MI5’s press department, later acting briefly as its director.In 1938 he wrote "Teach Yourself to Fly", a book designed to help flying students with the basics before entering an aeroplane.