The last chapter shows the consequences of the boy's change into savages and their ironic rescue from almost being totally destroyed. In order to smoke out Ralph and kill him, Jack starts huge fire which begins to envelope the entire island. Ironically, the smoke from the fire is seen by a British ship which sends a small crew to investigate. They think one of their planes might have gone down and they will find the pilot.
However, as the fire grows, it becomes apparent that not only have the boys smoked out Ralph, but they have also destroyed most of the vegetation on the island. The fire shows the power of the beast that has now been completely released. The consequences of the evil inside means the boys would have killed Ralph but also destroyed themselves by killing all the fruit trees and animals on the island. Fortunately for Ralph, the British navy arrives in time to save him.
The officer, who represents the society the boys left, cannot understand why the boys have become so savage. But, in the final irony of the book, the boys are sent back to the war-torn civilization that they had tried to escape at the beginning of the novel.
His [Ralph's] voice rose under the black smoke before the burning wreckage of the island...Ralph wept for the end of innocence, the darkness of man's heart, and the fall through the air of the true, wise friend called Piggy.
Thus ends Chapter 12 of "The Lord of the Flies." Ralph has lost his effectivness because of his inability to understand the reasoning behind his desire for civilization and rules; Piggy, his vision gone, has had his blind faith in a system of rules shattered as symbolically the conch breaks into pieces. His vision gone, Piggy, too, is perceived as dispensable.
Has savagery won over civilization or vice versa? The reader is left to resolve the allegorical tale of English boys stranded on an island and their "fatal unreasoning knowledge" of their regression into savagery represented by the shattering of the conch and the theft of Piggy's glasses in Chapter 11(the climax) as well as the use of such words as "the painted group" and "the tribe" and "the group of savages."
Without resolution, Chapter 12 sets images of the destructive force of the fire set by the "tribe" juxtaposed against images of the fire and its smoke effecting the rescue of the boys. Yet, even when the officer rescues Ralph, the man looks back at the ship,the trim cruiser of war in the distance. This glance suggests that violence will continue as the war still exists.
One thing is certain. As in Thomas Wolfe's novel, Ralph and the other boys "cannot go home again"; they can never return to the innocence that they knew before arriving on the island.