Arthur is also often assumed to be the most skittish of the group. For he is a 'reluctant' paranormal investigator, meaning that he may not be as fond of investigating paranormal events as his friends are. As Arthur was the one responsible for Lewis death, for he became possessed and pushed Lewis off a cliff to his death when they explored a cave one day. He doesn’t seem to remember that day but of course Lewis does. And his prosthetic arm is proof.