Towards the end of Chapter 9, Jack demands that his hunters begin their ceremonial dance as it starts to thunderstorm overhead. Roger plays the role of the pig, and the hunters surround him while they jab their spears, wave their clubs, and begin to chant. In the midst of the storm, Ralph and Piggy are drawn towards the group of boys and join along in the ritual. Golding writes,
Piggy and Ralph, under the threat of the sky, found themselves eager to take a place in this demented but partly secure society. They were glad to touch the brown backs of the fence that hemmed in the terror and made it governable.
Ralph and Piggy initially join the dance because they feel more secure around the group of boys during the storm than they do standing by themselves. They are also attracted to the frenzied environment of the ritual. Golding writes that their chanting became like a heartbeat as the group of boys moved in unison. Seemingly out of nowhere, Simon stumbles onto the beach, and the group of hunters encircles him. The group of boys initially mistakes Simon for the beast as they begin to savagely beat him to death. Piggy and Ralph participate in Simon's murder because they are in such a frenzied state of confusion and bloodthirst. They both get caught up in the excitement and cannot restrain themselves from participating.
There is a thunder storm at the time with much lightening. Ralph and Piggy feel more secure in the safety of numbers than they do on the periphery of the other dancing and chanting boys. Also, they are caught up in the frenzy just as the other boys are.
Ralph and Piggy join the dance because they are succumbing to their own weakness, exhaustion, and loneliness. A storm is coming, they are alone , and are tired of trying to keep the others from siding with Jack's tribe.
The fire and roasting pig are strong incentives for the pair, and weakness takes over, and they go. They are tired and hungry, and for a time , just want to quit resisting , and let someone else take care of them.
As the storm builds, the boys are ordered to dance. The excitement even affects Ralph and Piggy , so they dance until Simon makes his appearance.