Piggy's words from Chapter Eleven, "Castle Rock," of William Golding's Lord of the Flies, marks the turning point in the narrative. For, after Jack and the hunters have stolen the fire, the symbol of power and control as well as the tie to civilization, savagery has gained control of the island.
The rational Piggy realizes that without the fire, Ralph and his group exert no power over the hunters; consequently, the boys who try to remain civilized have nothing with which to negotiate since Piggy's glasses have also been stolen. When Ralph, Piggy, and Sam attempt a reasonable meeting with Jack and the others, Roger, who--with the power of the fire in his camp--has now given free reign to this sadism, balances a bolder overhead that is aimed for Piggy. Understanding
only too well the liberation into savagery that the concealing paint brought,
Roger, "painted out of recognition" like the other hunters, releases the pink granite boulder that strikes a glancing blow "from head to knee." Piggy plummets to his death. Jack screams to Ralph that he will be next. The conch is gone and he is chief; throwing his spear at Ralph, Jack symbolically jumps over the headless body of the pig much like Piggy's body that has also been decapitated, and throws his spear at the fleeing Ralph.
With Jack and the others reduced to savages, Roger's sadism is released "with delirious abandonment." This destructive force of Roger foreshadows more destruction, and marks the beginning of the total anarchy and devastation to civilization to the island now that its "last blind devotee has gone." Left too long without the controls of society, the boys have degenerated to destructive forces. As the last representative of civilized order, Ralph must flee before Roger and and the other "painted fools."
In the larger context of the story, Ralph is trying to get his own small society started and in doing so, he was trying to show that he could have fire and maintain it. Fire is a lifeline with any mode of survival and here, Ralph has failed. Essentially, if you don't have fire, you don't have what you need to survive. It will therefore be impossible for Ralph to maintain a group of kids under his terms, because Jack has fire and that is always a lure back to his side. Ralph's side is small to begin with, so this is the beginning of the end for his "tribe." Check out the link for more information on the characters and what they mean to the entire story.