Leonard is a shy, socially awkward 40-year-old boy who does his best to look after his elderly mother, Lena. He dances with her, feeds her and even bathes her before helping her to bed at night. She appears to be suffering from dementia, but her blank stare and feral appearance give the impression that she is up to sinister things. One night, funny things start happening and Leonard collapses in the hallway. When he came to, he saw that Lena was behaving very strangely. Johan, a naive member of the neighborhood watch, arrives, but he is completely unprepared for the horrors that await him.