In bed with covid and thinking about an old fashioned film maybe set the fifties.its about a man who i think is a widow with a young son. He marries a woman who is totally nuts and a narc,she is incredibly jealous and paranoid and when she gets pregnant tries to miscarry the baby, her sister who is lovely comes to stay and comes to realise what's going on. The scenery is gorgeous set by an American lake and in the end she takes his son out in a rowing boat and let's him drown (sounds dark i know but it was so good) any ideas?