Who shows leadership by going into the castle and on what page?

Lord of the Flies is the 1954 novel by British author William Golding (1911—1993) which tells the tale of a group of boys stranded on a remote island who descend into tribalism and savagery.
On page 105 of the 2003 Penguin Books printing of Lord of the Flies, part of the marooned group of boys approaches a small, rocky outcrop at the end of the island. This natural structure will become known as "the Castle Rock" and it will be here where Jack makes his headquarters.
However, it is Ralph who first enters "the castle," resolving that since he is the chief he should be first to go. He leaves with the final instructions for the group to hide and wait for his return. Ultimately, however, Jack follows him in saying "I couldn't let you do it on your own."