John Buchan 
Greenmantle 

Greenmantle is the second of five novels by John Buchan featuring the character Richard Hannay. It was first published in 1916 by Hodder & Stoughton, London. The plot of Greenmantle involves the uncovering of a German plot to incite an Islamic uprising in the Middle East that will cause Britain and its allies to divert troops from the Western Front. The action moves from wartime Germany, through Europe to Constantinople as Hannay and his comrades seek to disrupt the plot. In Greenmantle (1916) Richard Hannay, hero of The Thirty-Nine Steps, travels across war-torn Europe in search of a German plot and an Islamic Messiah.