King of the Khyber Rifles

It is August 1914, and the British in India are watching the Khyber Pass more nervously than they watch Europe. Captain Athelstan King goes up into the hills alone, ordered to find out who is stirring the tribes toward a holy war while Britain’s regiments sail off to France. What he finds is Yasmini, a princess whose loyalties shift by the hour, a mullah preaching slaughter, and a cave system under the mountains that owes more to Mundy’s theosophy than to any survey map. Mundy had lived in the region, and the frontier detail holds even after the plot turns mystical. It became his most popular book by a wide margin. Available here as a free PDF and EPUB edition.