Mystique(1979)

Alma, a famous photographer, needs to move away from work and the city due to a serious cancer illness, and will live alone in a beach house. Surrounded by award-winning photos of her past, and haunted by memories, she ends up getting involved with Cosima, a young woman from the neighborhood. But what begins as a love affair between the two women soon turns out to be a nightmare when Cosima starts manipulating Alma and bringing others into the house - and their lives.