The Restless Dead — Hugh B. Cave

A curse lingers over the Everol mansion -- a .voodoo curse, born of evil, steeped in blood. The tormented family who lives in this house of horrors is beset by insanity, visions ... and death. They have shut themselves off from the world, allowing no one to trespass on their blighted property. No one except Jeff Gordon, a university professor with a special knowledge of voodoo and the occult. Reluctantly, in desperation, the Everol family has permitted Gordon to enter the mansion. But all Gordon's experience could never prepare him for the unearthly creatures that await him there -- or the ultimate terror of the mysterious caves beneath the house.