Off-her-rocker Ethel (super lethargic weirdo off-her-rocker, not bats*** crazy hysterical off-her-rocker) usually is institutionalized like a good weirdo but somehow finds herself on the side of a road. She's wandering about a car crash site where she does cute things like putting a stone into the mouth of all the dead people from the crash. Some more or less helpful guys drive her to an address that they think is her home, but it is the house of the sister who used to take care of her until she had enough of the family loon. How will the sister react and what will she do with Ethel? But maybe more importantly what will Ethel do and in her own mind what will she think she is doing?
The American Gothic novel "We Have Always Lived in the Castle" by Shirley Jackson is one of my favorite books. The protagonist of that novel is the very strange 18-year-old Mary Katherine Blackwood, also simply known as Merricat. The thing is that we experience everything through her skewed perception, it's not so much Merricat who appears strange, but everybody else does. This makes her likable to the reader even as she does and thinks quite evil things. Ethel basically is Merricat ten years later, and she only drifted even further into her own world. For another point of reference think of Norman Bates in the last scene of 'Psycho' (the fly).
Like Merricat we don't really know much about Ethel and we only pick up a few pieces here and there. She's a mysterious character and remains mysterious until the end. And like "We Have Always Lived in the Castle" we see the world tainted in the protagonist's colors and it's all a bit funny in its strangeness. We hear a lot of Ethel's cute ideas, like, she's convinced she can make bad things happen to people just by motionlessly sitting, staring at the floor and concentrating very hard or whatever. Don't expect any logic or consistency in her thoughts. One particularly cute idea of hers is that her sister moved all the furniture, the doors, the staircase, etc from one side of the house to the other since the last time Ethel was there, left is now right, and right is left. She's terribly amused by the fact that her sister must have put enormous effort into moving everything just so that in the end everything looks basically the same as before.
I would like to see a movie adaption of "Castle". 'You Are Not I' isn't it, but to me it kind of had the novel's feel and with the parallels between the protagonists I could consider it a spin-off in spirit. 'You Are Not I' is in black and white and very slow paced. Much of it isn't terribly exciting but the ominous atmosphere keeps it compelling and it makes up for any lengths with an ending that is both revealing about Ethel's character and wonderfully ambiguous and chilling. Not that the film would have to make up for much, it's 46 minutes short.