At the palace of the Emperor of an unidentified island in the West Indies, Smithers, a Cockney trader finds that all of the servants have left except for one old native woman. He interrogates her to learn that the natives are plotting a revolution against the Emperor, an American fugitive named Brutus Jones.
When Jones awakens, Smithers warns him of the plot and the danger of trying to make an escape through the dark forest of the island. Jones scoffs at the idea that his illiterate, uneducated, and superstitious subjects are capable of outsmarting him. He confesses that he knew this day would arrive when he took the throne, since he has been stealing from the island an hiding a fortune in a foreign bank account.
As Jones sets off to escape from the revolutionaries, his mental state gradually collapses in the darkness of the forest. Jones is overconfident due in part to the fact that he has convinced the islanders that he possesses magical powers. After an earlier attempted assassination, Jones successfully constructed the myth that he can only be killed with silver bullets.
In the darkness, Jones sets off into the forest with a gun loaded with five lead bullets and one silver bullet. He begins seeing hallucinations of his innermost fears, in spite of being alone. As he encounters each hallucination, he fires a bullet from his gun that has the rather counterintuitive effect of alerting his pursuers to his whereabouts.
Through hallucinatory imagery and Jones' monologue we learn that Jones came to the island as a stowaway on a boat after killing a man over a game of craps and then killing a prison guard to escape from jail. He has visions of the man he killed as well as the prison guard.
His next hallucinations are a slave auction, a slave ship, and a Witch-Doctor in the Congo, who tries to kill him with the help of a hungry crocodile. He shoots at the crocodile with the last remaining silver bullet.
Smithers returns to the play in the final scene, and meets up with the leader of the insurrection, Lem, who previously tried to shoot Jones. The revolutionaries set out into the forest to find Jones.
Shortly after, Lem returns to tell Smithers that they killed Jones. Lem tells him that he and the other revolutionaries melted down silver coins to make silver bullets that would kill Jones.