What does the signal fire represent in Lord of the Flies?
The signal fire in the story is a symbol of hope of the boys' return to civilisation. By keeping the signal fire going they hope to attract the attention of a passing boat or aircraft who will then rescue them. It starts off on the mountain but then later moves to the beach. Because it is linked so closely with the boys' return to civilisation, it becomes an indicator of the boys' connection to civilisation. For example, in the early parts of the novel the boys want to maintain the fire and keep it going which is a good sign as it shows they want to be returned to civilisation. However, when the fire is allowed to burn low or even goes out, it is highly symbolic of their rejection of civilisation in place of the barbaric savagery that runs amok on the island. It is highly ironic that at the end of the novel a fire does attract a ship, but it is not the signal fire, instead it is the fire that Jack and his mob start to hunt and kill Ralph.
One key passage that demonstrates this is in Chapter 4 when Jack and his hunters neglect their responsibility to keep the signal fire going and go and hunt and kill a pig instead. Ironically, this is when Ralph and Piggy can see a ship on the horizon, who of course does not know they are there because the signal fire has gone out. We see here that Jack and his hunters are more interested in hunting and savagery and satisfying their blood instinct than they are with rescue and return to civilisation.