Every person Marlow meets on his venture contributes something to the plot as well as the overall symbolism of the story. Kurtz is the violent devil Marlow describes at the story's beginning. It was his ability to control men through fear and adoration that led Marlow to signify this. Throughout the story Conrad builds an unhealthy darkness that never allows the reader to forget the focus of the story. At every turn he sees evil lurking within the land.
Every image reflects a dreary, blank one.
The setting of these adventurous and moral quests is the great jungle, in which most of the story takes place. As a symbol the forest encloses all, and in the heart of the African journey Marlow enters the dark cavern of his won heart. It even becomes an image of a vast catacomb of evil, in which Kurtz dies, but from which Marlow emerges spiritually reborn. The manager, in charge of three stations in the jungle, feels Kurtz poses a threat to his own position. Marlow sees how the manager is deliberately trying to delay any help or supplies to Kurtz.