what happens to the fire they build? LOTF chapter 8

Are you sre you mean chapter 8? When Jack leaves, Ralph says that he thought Jack was going to take the conch, which Ralph still considers a symbol of ritual and order. They reassure each other again that the fire is the most important task at hand. But a boy among them named Bill appears skeptical. He suggests that they go to the hunters' feast and tell them that the fire is hard on them. At the top of the mountain remains the pig's head, which Simon has dubbed the Lord of the Flies.