As the curse takes hold, Billy's life spirals out of control. His physical health deteriorates, his friendships and family relationships become strained, and his legal career is jeopardized. Desperate to break the curse, Billy seeks help from a psychic named Gina Lempke (Lucinda Jenney), who guides him on a journey to understand and confront the Romani culture and its spiritual beliefs.
Throughout the movie, Billy encounters various characters, including a relentless private investigator (Joe Mantegna) hired by the gypsy community to ensure the curse's fulfillment and a mysterious old man named Taduz Lemke (Michael Constantine), who may hold the key to lifting the curse.
As the story progresses, Billy undergoes a profound transformation as he learns about the consequences of his actions and the power of forgiveness. "Thinner" explores themes of guilt, morality, and the supernatural, delving into the darkness that lies within human nature.