I remember a story about twin sisters. They move to a new town where no one knows them (as I remember it) and buy a house. They either build or find a cell in the basement. One of them is always kept locked in the cell naked by her sister. Every so often (monthly as I remember) they play a card game and the looser has to spend the next month in the cell. They have a job which they share, their coworkers never realizing there are two of them.
Is that jogging anybody?