Richard Hannay arrives in London on the eve of World War I, where he meets an American agent seeking help in stopping a political assassination. Before long, Hannay finds himself in possession of a little black book that holds the key to the conspiracy - and on the run from both the police and members of a mysterious organization that will stop at nothing to keep their secrets hidden.

After working as a mining engineer in southern Africa, Richard Hannay is in London and at a loose end. When a man is killed, Hannay is suspected of the murder. He flees to Scotland and becomes embroiled in an international spy ring related to the mysterious "39 steps." Hannay must elude both the police, who are hunting him for murder, and the foreign spies who seek to foment war.

Greenmantle is the second of five novels by John Buchan featuring the character of Richard Hannay. Hannay is called in to investigate rumours of an uprising in the Muslim world, and undertakes a perilous journey through enemy territory to meet his friend Sandy in Constantinople. Once there, he and his friends must thwart the Germans' plans to use religion to help them win the war, climaxing at the battle of Erzurum.

Greenmantle is the second of five novels by John Buchan featuring the character of Richard Hannay. Hannay is called in to investigate rumours of an uprising in the Muslim world, and undertakes a perilous journey through enemy territory to meet his friend Sandy in Constantinople. Once there, he and his friends must thwart the Germans' plans to use religion to help them win the war, climaxing at the battle of Erzurum.