This is one of those movies in which you're not sure if things are really happening or if they're solely in the mind of the main character.
Jessica (Zohra Lampert), recently released from a mental institution, moves out to an island on the East Coast with her husband and a friend. But everyone in the town acts weird and they have these scars on their necks. Jessica also sees a pale human body underneath the water and begins to think that the a woman who shows up is really a vampire...
This is one creepy movie and holds up well over time. SHOCK WAVES, made a few years later, is very similar in structure.
This is one of those movies in which you're not sure if things are really happening or if they're solely in the mind of the main character.
