"Thinner" is a horror novel written by Stephen King under the pseudonym Richard Bachman. The story follows a man named Billy Halleck, who, after a chance encounter with a mysterious Gypsy, is cursed to lose weight uncontrollably. As he becomes dangerously thin, he struggles to find a way to reverse the curse while dealing with the consequences of his actions. The novel explores themes of guilt, revenge, and the impact of one's choices. It highlights how a seemingly simple curse can lead to devastating effects on a person's life, relationships, and sense of self.