Ellen, a successful astronomer, cares for her mentally-ill sister, Cissy, who keeps a variety of primates in the home they inherited from their anthropologist father. When Ellen begins a romance, Cissy's jealousy proves deadly.

Two strange sisters live in a crumbling mansion, where they keep a pet ape, which belonged to their late father, locked in a cage. While one of the sisters seems to be keeping her head on straight, as it were, the other appears to be sinking further and further into barbarism and insanity.—[email protected]