What did bill tell sam when he returned from poplar cave what made him do what he did?

When Bill returned from Poplar Cave, he told Sam about the haunting experience he had there, which deeply affected him. He explained how the eerie atmosphere and unsettling sounds made him confront his fears and question his past choices. This revelation compelled him to take action, leading him to make significant changes in his life. Ultimately, it was the confrontation with his own demons that drove him to do what he did.