Spider Baby or, The Maddest Story Ever Told

In a dilapidated rural mansion, three orphaned siblings - Ralph, Virginia, and Elizabeth - live in seclusion with their family chauffeur Bruno (Lon Chaney Jr.), who covers up their indiscretions. As they regress mentally and physically due to the inherited Merrye Syndrome, they exhibit playful innocence mixed with feral madness. When greedy distant relatives and their lawyer arrive to dispossess them of their home, Virginia, the most responsible of the three, becomes a sadistic killer, while her sisters' darker impulses unfold, leading to a chaotic and violent confrontation that ultimately leads to destruction and tragedy.