Joseph Conrad uses a frame structure in Heart of Darkness. This frame establishes a preliminary location and an initial narrator, located in England. The atmosphere of a pleasant excursion on the River Thames in London might be familiar to readers of English novels. The second narrator is Marlow, who offers a tale about a very different environment. It has an element of similarity in that both settings include a river. Once Marlow’s voice and his concerns are established as the predominant perspective, they do not let up until the novel’s conclusion, which returns the reader to the present and to England.
By using Marlow as a first-person narrator of his own story, Conrad creates two contrasting ideas in the reader’s mind. On the one hand, Marlow presents himself as an eye-witness to the events he narrates. In this manner, the author makes Marlow’s story seem like factual testimony. Marlow draws the audience in to his story, transporting them to a distant and unfamiliar land, and he accentuates the darkness, or incomprehensible and unenlightened qualities of both the environment and the people he meets there. On the other hand, Marlow alone bore witness to those events—some of which seem utterly fantastic as well as grotesque—and therefore constitutes an unreliable narrator.
Rather than solve a mystery, Conrad raises further questions about what “really” happened in the Congo, including the relative sanity of Marlow—not just of Kurtz—as a man who took a metaphorical journey into the darkness of the human soul.