Ralph is dreaming of home when the twins wake him up screaming that they saw the beast and that it was furry, had wings, teeth, and claws, there was something moving behind its head, and it followed them by "slinking behind the trees."
By now, other boys have gathered around to listen, including our favorite troublemaker, Jack.
Naturally Jack wants to hunt the thing down.
Jack, Ralph, and an assortment of biguns head off to do so.
When Piggy asks who's going to look after the littluns while everyone else is off hunting for the beast, Jack says, "Sucks to the littluns."
On that charming note, they let the hunt begin.
They decide to head for the tail end of the island, where the rocks make a sort of bridge that they call "the castle."
Simon is doubtful that there's really a beast. He imagines "a picture of a human, at once heroic and sick."
When they get to the rocks, Ralph declares that, since he's the chief, he'll look for the beast.
Several heart-pounding moments later, he sees that Jack has followed him.
Not surprisingly, there is no beast inside. They have some fun exploring. And then they decide to climb to the top of the mountain to look for this beast thing.
The other boys start swarming into the rocks, having a grand old time, until Ralph realizes the signal fire has gone out again.
With much grumbling and muttering, the boys follow Jack and Ralph to the top of the mountain.