Dementia 13 (1963)
Considered by many to be progenitor of the "slasher" film, Dementia 13 revolves about a creepy Irish family returning to their ancestral castle to remember the death of their daughter Kathleen who drawned on the nearby lake seven years ago. When the patriarch of the family suddenly dies, Louise gets rid of the body and tries to get the family inheritence. Soon, however, the family members become the target of an axe murderer.