In the backdrop of the story, a world war is taking place and the events on the uninhabited tropical island serve as a microcosm of what is currently happening in the outside world. The characters in the story are directly impacted by the war, which is why they are on the island in the first place. The boys' plane is initially shot out of the sky by a missile at the beginning of the story and an air battle is fought in the sky directly above the island. Initially, Ralph believes that his father, who is a commander in the Navy, will eventually rescue them and instructs the boys to create a signal fire on the top of the mountain.
Unfortunately, Jack allows his hunters to dismiss the signal fire, which goes out moments before a ship passes the island. After losing a rare opportunity for rescue, Jack gradually undermines Ralph's authority and chaos ensues on the island. By the end of the story, Jack and his hunters start a massive forest fire in an attempt to smoke Ralph out of his hiding spot. Fortunately, Ralph manages to avoid the hunters and stumbles onto the beach, where a British naval officer is standing. The officer asks Ralph if there are any adults on the island and Ralph looks at the sky, which is completely black. The Navy officer then tells Ralph,
We saw your smoke. What have you been doing? (288)
Essentially, the Navy officers noticed the massive black clouds above the island and decided to see if there was anybody living on the island. Jack's forest fire ended up catching the attention of a passing ship, which happened to be part of the Royal Navy.