A girl lives in a house with her parents. There is a cellar door in the house, and her parents warn her to never, ever, open it because she's not ready to see what's behind it.
What is on the other side of the door that her parents don't want her to see?
The girl is locked in the cellar. Her parents are both crazed people who thought the best way to protect their daughter would be by locking her in the cellar since she was born. On the other side of the door is the rest of the house, and the outside world.
A man murders his wife with a knife in their car. Nobody is around to see this. He throws her out of the car being careful not to leave any fingerprints on her body. Next he throws the knife off of a cliff into a gorge where it will never be found and he goes home. An hour later the police call him and tell him that his wife has been murdered and he needs to come to the scene of the crime immediately. As soon as he arrives, he is arrested.
He never ask the cop where the scene of the crime was so they knew that he had murdered his wife.