Having approached the island in sweltering weather, the crew is irritable and discontent. Dr. Livesey warns the men that they may be at risk of contracting tropical diseases on the island. Silver, with his knowledge of the island’s geography, advises Captain Smollett of a good place to drop anchor. Smollett does not reveal what he knows about the planned mutiny. After consulting with Squire Trelawney, he decides to allow the crew to go ashore for diversion, which allows the honest men to reclaim control of the ship.
Smollett takes Tom Redruth and several other honest sailors into his confidence and gives them weapons. Silver leads the pirates ashore, believing that they will be able to recover the treasure immediately. Jim, deciding that his assistance is not needed on board, hides in one of the pirates’ boats and goes ashore with them. However, Silver catches sight of Jim, who begins to regret his decision. Reaching the shore before the others, Jim quickly scrambles away from them.
As Jim surveys the island, he is startled to hear voices nearby. He creeps closer and finds Silver addressing one of the sailors named Tom, trying to persuade him to join the mutineers. Silver makes it clear that Tom’s life is riding on his decision, but Tom declines politely but firmly. They suddenly hear a piercing scream from far away, and Tom is greatly alarmed. Silver says coldly that the scream must be from Alan, another honest sailor who has refused to join the pirates.
Tom tells Silver that Silver is his friend no more and starts to walk away. Silver flings his crutch at Tom’s back, knocking him down, and then walks over and kills him with his knife. Jim is terrified, realizing that he has no way to get back to the ship without being spotted and killed by Silver and his gang. Jim starts to run deeper into the island.
Fleeing the pirates, Jim sees a human figure in the woods, and he fears that it is a cannibal. Suddenly remembering he is armed, Jim gains courage and walks briskly toward the man, who is hiding behind a tree. Jim asks the man his name, and the man replies that his name is Ben Gunn and that he has been on the island for three years. Jim asks Ben if he was shipwrecked, and Ben answers that he was marooned. Ben speaks in a deranged manner, making many religious allusions. Jim suspects that Ben may be mad.
When Ben asks if the ship moored on the shore is Flint’s, Jim realizes the wild man may have useful information. Jim learns that Ben once served on Flint’s crew and thus knows all the current mutineers. Ben was left behind on the island after a failed treasure hunt three years ago. Jim learns that Flint buried his treasure and killed the six men who helped him bury it. Ben also mentions that he made a boat, which he hides under a white rock. He assures Jim that he can locate the treasure in return for safe passage home, and guides Jim to his dwelling. On the way there, Jim is startled to see the Union Jack, the gentleman sailor’s flag, proudly waving in the distant woods.