It only grows at night. Karen Tandy is a sweet and unassuming girl until she discovers the mysterious lump growing underneath her skin. As the doctors and specialists puzzle over the growth, Karen's personality drastically begins to change. The doctors decide there is only one thing to do, cut out the lump. But then it moves! Now a chain reaction has begun and everyone who comes in contact with Karen understands the very depths of terror. Her body and soul are being taken over by a black spirit over four centuries old. It is the memory of the evils the white man has bestowed on the Indian people and the vengeance that has waited four hundred years to surface. It is the Manitou.