A renegade sheik named Ali Higg, known as the "Lion of Petra," has become a danger to British interests in Palestine. Jimgrim is an American secret agent working for British Intelligence who seeks to undermine Ali Higg's plans to raid British controlled territory and win him as an ally instead. He is joined by his compatriots Jeff Ramsden and Narayan Sing, a Sikh, who is very dangerous warrior.

Talbot Mundy (1879-1940) was an English-born American writer of adventure fiction. Mundy spent his early adult years in India, East Africa and Middle East, and many of his novels and stories are set in that part of the world. He is best known as the author of King of the Khyber Rifles and the Jimgrim series.