In the darkness of the 10th century A.D., Theodorus Philetas, a university professor, is forced to flee from Constantinople to Damascus with his friends, the Arab Bashar ibn Fathi and the young Leon Peleuses, following an unsuccessful conspiracy against the emperor. Leon stumbles upon a forbidden book kept hidden by a Jewish merchant, Joel, and his beautiful daughter, Rebecca. Theodorus comes upon the book, which proves to be nothing less than the notorious Al Azif by the mad Arab Abdul Alhazred. Forced again to flee, Theodorus goes to Cyprus, taking the book with him. Reading it, he begins...