His breakdown occurs only in chapter 9 and so does his death. After they find what they believe to be the beast, he decides to go on his own, not to leave the group permanently, but to go investigate the mountain on his own for a while. The first thing that may have caused his breakdown, though we can't be sure, may have been when he found the body of the pilot that had fallen from the sky sometime earlier in the book. “The flies had found the figure too. The life-like movement would scare them off for a moment so that they made a dark cloud round the head. Then as the blue material of the parachute collapsed the corpulent figure would bow forward, sighing, and the flies settle once more” (p. 210) Anyone could agree that that would be a bit traumatising to anyone, especially a young boy who was likely already beginning to lose hope of ever seeing the world he once knew of again. After that incident, he stumbles on the head of the sow that had been killed by Jack and his crew, only to have fantastical visions, or delusions, involving it. He may have reached some helpful conclusions through these delusions, that the beast was not something they could fight or needed to fear, that it was actually their inner urges to destroy and be wild, but there is no denying that the pig’s head did not actually talk to him and anything he saw was made in his own mind. As helpful as this information could have been, Simon was soon killed by the other boys after they worked themselves into a frenzy and mistook him for the beast. “Kill the beast! Cut his throat! Spill his blood!...Him! Him!” (p. 218) This chapter was one of the most madness driven in the book, showing not only Simons, but also everyone else in the…