Sisyphus, the king of Ephyra, was renowned in Greek mythology for his ingenuity; indeed, so clever was he that he cheated death twice, angering the gods. They took their revenge by condemning Sisyphus to eternal torment in the underworld: He had to roll a huge boulder up a hill. When he reached the top, the stone would roll back down to the bottom, and he would have to start all over, on and on, forever.