Richard Hannay, a mining engineer on holiday from the African colonies, finds London socialite life terribly dull. Yet it's more than he bargained for when secret agent, Scudder, bursts into his room and entrusts him a coded notebook with map, concerning the impending start of World War I. In no time both German agents and the British law are chasing him, ruthlessly coveting the Roman numerals code, which Hannay believes he must crack himself. Masquerading as a liberal party pundit, Richard also gets stuck with parliamentary candidate Sir George Sinclair's sister Victoria. They must survive with the secrets and decide who they can trust and how to keep it from others.