Neither gold nor diamonds, but a far more valuable treasure is said to slumber within a mountainous stronghold somewhere in the Sahara. Two men have always dreamed of finding it: archaeologist John Shannon and his brother Michael. But Michael, who has never forgiven John for stealing the woman he loved, has become John's most embittered enemy and is determined to prevent John from finding the Tower. When John vanishes in the Sahara, his daughter Diane resolves to find him with the help of Rashid, an Arab desert prince who loves her, but who has also vowed to protect the secret of the tower. Meanwhile, in the Sahara, John comes face to face with his brother Michael, who now calls himself Zadik and rules over a band of marauding warriors who spread fear and terror in the desert. Though captured and nearly killed by his brother, John manages to escape and continues his quest...