The document discusses the theme of uncertainty in Joseph Conrad's novella Heart of Darkness. It summarizes that uncertainty is embedded throughout in the narrative structure, ambiguous descriptions of the environment and characters, and recurring images of darkness. The structure being a story within a story makes it unreliable. The jungle is depicted as mysterious and foggy. Characters like Kurtz are enigmatic figures with both noble and destructive impulses. Darkness represents the blurring of lines between good and evil. The entire journey is filled with a sense of unknown danger and lack of surety.