Tower of Fear — Glen Cook

The Witch entered the temple as the men met. She gasped, unable to believe even now that she saw it. How had the man gotten through the citadel's defenses? What man could have earned such great power?

Clouds of light and shadow contended. Larger than life, figures turned in an almost formal, elegant dance around the slice and dart of flashing mystic blades.

The shadow was overpowering the light slowly, consuming it, but she did not see that in her fear for the man she loved. She saw only that an enemy was trying to kill him and that enemy was a great enough wizard to have penetrated the citadel's impenetrable defenses. She screamed, all reason fled before the prospect of loss. "Nakar!"

Startled, the shadow turned her way.

The light struck its blow.

... and so begins a tale of doom and wizardry that brings us all, in the end, to

The Tower of Fear