At this stage of the story we see Ralph and the hunters go to the top of the mountain on their mission to find 'the beast'. It is very significant because the boys mistakenly believe that they have found the beast and thus have their worst nightmares confirmed. However, this event is also significant because despite the outward signs of cooperation between Jack and Ralph, the animosity Jack feels towards Ralph continues to seethe not far beneath the surface.
Ralph, Jack and Roger are the only ones who volunteer themselves to go to the very top of the mountain at night. Ralph is willing because he takes his leadership seriously, Jack is anxious to go to prove himself braver than Ralph and Roger's motivation is not made clear. The logical side to Ralph's thinking quickly tells him that to proceed at night is foolhardy, but Jack only sees this as an opportunity to deride him for being scared. His challenge is mostly directed at Ralph, although clearly Roger too has major reservations about proceeding any further. "Windy?" (p. 149) is the taunt that Jack uses, which is a slang expression from the time for being scared. He further demeans the boys by saying, "If you don't want to go on," said the voice sarcastically, "I'll go up by myself." (p. 149).
Whilst Ralph and Roger do eventually go to the top of the mountain, the significance of this chapter is the failure of the boys to discover the truth behind 'the beast'. Indeed, their fears are only severely worsened. We also see the depth of Jack's hatred of Ralph even though they stood shoulder to shoulder on the beast hunting expedition. Soon after this event their relationship breaks down completely and the island community slides into complete depravity.