In Lord of the Flies, why do Ralph and Piggy decide to visit Jack's camp?
In chapter 11, of the older boys, only Ralph, Piggy, and Samneric have not joined Jack's tribe. Jack has previously stolen Piggy's glasses in a night raid, and Piggy is nearly blind without them. Not only that, but their signal fire has gone out, and without Piggy's glasses, they have no way to light it, so their hopes of rescue have plummeted.
Ralph calls an assembly of the four boys, and they decide to go to Jack's camp. Ralph's intent is to call an assembly, reason with Jack and the other boys regarding the fire, and obtain Piggy's glasses back. Ralph and Piggy are harboring a growing sense of outrage at Jack's savagery. Ralph is furious that Jack stole their means of keeping the fire lit. Once again, he is amazed that the boys can be so short-sighted, but he retains some hope that he can make them see reason. Ralph wants to wash up and go as representatives of the power of civilization, but his unruly hair and the horrible state of their clothing make that impossible. However, he insists they will not paint themselves; they will take the conch and go with dignity, showing the superiority of order and morality.
Piggy is also outraged at the personal cruelty he has experienced at Jack's hands. Although he primarily wants his glasses back, he also intends to confront Jack about his lack of morality. He wants to emphasize to Jack that "what's right's right."
When they reach Castle Rock, Ralph first states that he is calling an assembly. Then he accuses Jack of being a thief and demands he return Piggy's glasses. Then, although Piggy has to remind him, he explains that the signal fire must be kept lit because it is their "only hope." Without it, they might wait years until a ship comes near them by accident. After Ralph says his piece, Jack captures Samneric and tussles with Ralph. Then Piggy begins addressing the boys, telling them they are "acting like a crowd of kids." He asks a series of rhetorical questions of the boys, comparing Ralph's ways to Jack's ways. Roger answers each of his questions with stones thrown at Piggy from above. Finally, he rolls the boulder down on Piggy, killing him and shattering the conch.
Both Ralph and Piggy carry out their intentions when they arrive at Castle Rock, but the consequences are much more dire than they ever expected.
In Lord of the Flies, Ralph is voted chief when he blows the conch to call all the boys together after they are stranded on a deserted island. Jack accepts Ralph's position as chief but constantly tries to undermine that position and assert himself as rightful chief. After all, Jack points out that he is "head chorister" which he thinks makes him the natural choice.
Eventually, and despite Ralph and Piggy's best efforts, Jack is now almost in control of the activities on the island. He has Castle Rock and more supporters and now he has "meat." Even Piggy is tempted by the thought of meat instead of interminable fruit. In chapter 9, Ralph and Piggy discuss the fact that the other boys have gone to "Jack's party" and Piggy makes the suggestion that he and Ralph should go "to make sure nothing happens." This is why they decide to visit Jack's camp.
Only a few of the boys, Ralph, Piggy and Simon are not at the party, or feast, and everyone else is having fun and enjoying themselves, but as Ralph and Piggy approach, they all go silent. However, before long, Ralph and Piggy are also eating the meat, although Ralph feels uneasy and even recognizes "the threat of violence. Ralph and Jack argue over who the real chief is but they are interrupted by a storm and Ralph and Piggy get caught up in the frenzy that follows.
Piggy is desperate to get back his glasses which have been stolen by Jack and his tribe. He convinces Ralph, in his position as leader, to go with him because "right is right" and he (Piggy) deserves to be given his glasses.