What one reason does Jim Hawkins have for staying hidden from John Silver and his men?

The first thing that comes to mind in Jim hiding in the barrel. He had to stay hidden because the pirates were planning a mutiny. He likely would have been killed if discovered.

The first thing thing that came in Jim's mind was that to remain hidden in the apple barrel. He had to stay hidden so he could hear all of the plans of the mutineers and inform about it to his mates and if he came out of the barrel, he was likely to be killed.