The Corridors of Fear — Clarissa Ross

Pretty young Angela Rome had only been married a short while when her husband Gilbert left on an Egyptian archaeological expedition. But when he returned, she sensed he was not the same man who went away. Something had happened to him, changed him, something involving the bizarre entourage he brought back to the castle - especially the strange Egyptian girl who never walked in daylight.

As the days wore on, quiet terror mounted in Angela. There were reports of wild attacks on the villagers, her own life seemed constantly in danger - and the castle continued to fill with an evil that had no name and knew no limits...