A southern belle takes a wrong turn in the swamp and ends up in a house of horror in this densely atmospheric Thriller. On her way to a romantic interlude on a stormy night, young teacher Marcia comes to a dead end in her car in front of a remote dilapidated mansion. Suddenly, shots ring out and, in a panic, she drives into a ditch and is knocked unconscious. Marcia wakes up to find herself the unwilling guest of the weird reclusive Herrod family, in a house that seems to be haunted by a blood-sucking poltergeist. She vainly struggles to persuade the Herrods to release her but the man of the house, Victor, is a weak-willed drunkard and the it seems the real head of the family, the wretched miserly Granny Herrod (Jeanette Nolan), is determined that Marcia not bring stories of the Herrod family "secret" back to civilization.
An ideal episode of Thriller in outline, Parasite Mansion is only hampered a bit, ironically, by one of it's greatest features: Jeanette Nolan's outstanding performance as the oppressive harridan Granny Herrod. Her character's relentless antagonism sort of lets the cat out of the bag early on in the story and makes Victor out to be a profoundly stupid individual for putting up with her abuse for so many years.
Another treat in Parasite Mansion is the casting of the terrific child star Beverly Washburn as Lollie Herrod, the youngest and most innocent victim of the Herrod family curse. She does a very good job portraying the tormented Lollie, whose shy child-like character otherwise wouldn't have made much of an impression. A few years later, Washburn would portray another feral young girl in an old house with a weird family in Jack Hill's classic Spider Baby, this time in a role with a little more dimension. 8/10