Later

Introduced by Professor Marty Burkett, the Ritual of Chüd requires Jamie to literally embrace the evil that haunts him. Only when he embraces Therriault/The Deadlight can he take it into himself and control it. Symbolically, he is confronting his own dark side—in this case, his ability to speak to the dead (and the responsibility that comes with it). However, while Jamie can coax truth from the dead, they can also haunt him.

Jamie would rather let the deadlight go and be rid of it forever, but the message of the ritual is that one can never be free of darkness. If one tries to escape it, it will be able to control them. In order to take his first step toward adulthood, toward manhood, Jamie can’t change his mind and push his demon away. After Jamie performs the ritual, Professor Burkett warns him to never call on the demon—however, Liz forces him to summon his inner darkness. But unlike Liz, Jamie wields his darkness in a responsible way.

Stephen King uses the motif of illness, both physical and mental, to represent the consequences of giving in to one’s inner darkness. Uncle Harry gave in to temptation and lust when he took advantage of his younger sister Tia, Jamie’s mother— though the novel doesn’t specify the exact circumstances of Jamie’s conception.