Greenmantle (The Richard Hannay Series‪)‬

In Greenmantle, Richard Hannay, hero of The Thirty-Nine Steps, travels across war-torn Europe in search of a German plot and an Islamic Messiah. He is joined by three more of Buchan's heroes: Peter Pienaar, the old Boer Scout; John S. Blenkiron, the American determined to fight the Kaiser; and Sandy Arbuthnot. Greenmantle himself is partly modeled on Lawrence of Arabia. The intrepid four move in disguise through Germany to Constantinople and the Russian border to face their enemies—the grotesque Stumm and the evil beauty of Hilda von Einem.