Are there parallel dimensions in which history turned out differently? Are there other universes with other Earths where the alternates became the realities? Here is an exciting science fiction novel of such an historical bypass. Told with the color and romance of the Crusades, reminiscent of the work of Harold Lamb and L. Sprague de Camp, what would have happened had the Knights Templars really made the demoniac alliance claimed by their royal rivals?
The "demon" was Baphomet - a stranded extra-terrestrial - and his alliance gave the Templars the atomic arms and scientific equipment to create the empire Baphomet needed for his own outer-space motives.