Declare by Tim Powers

Declare is a supernatural spy novel by Tim Powers. It presents a secret history of the Cold War in which an agent for a secret British spy organization learns the true nature of several beings living on Mount Ararat. In this he is opposed by real-life communist traitor Kim Philby, who did travel extensively in the region. Philby's father, St. John Philby, was a noted Arabist whose book The Empty Quarter was extensively used as source material for the novel.