The Dark Gate

At the center of the city of Satyrn, where the five Black Roads meet, the Black Tower, an ancient structure of unknown origin, rises high over everything else. Kharl, the most powerful mage in Satyrn, is building his magical matrix in a secret chamber beneath the Black Tower, where it draws on all the mana in the city and, through the Black Roads, the surrounding landscape, and concentrates it for his use. If he can complete his matrix before the night of the full moon he will open a dark gate and let Shigg'rath, the Dweller Beneath, come through. With Shigg'rath behind him he intends to carve out an empire and rule the world.
Kharl is using Sen, a shadow warrior with no memory of his past, as a master thief to acquire essential components for his matrix. Kharl has only four days left and the final, crucial piece, the Eye Of Yog, is secure in Yog's temple, and his need for the Eye is known. The only person who could stop him has been incorporated into his matrix but, unknown to Kharl, that man's daughter, Zorena, has already torn herself away from her normal life and come to Satyrn to take up the fight against him.
Sen struggles to define himself as his loyalties are tested from all sides. He starts to think for himself and agrees to work with Zorena, but Kharl brainwashes him again and uses him to steal the Eye Of Yog from the temple. One of Kharl's men, resenting Sens privileged position, double-crosses Kharl, takes the Eye, and flees from the city, presenting problems for Kharl and opportunities for his opponents, but the matrix has made him so strong he seems unstoppable.