Joseph Conrad crafted Heart of Darkness using a nested narrative structure involving two distinct narrators. The novella opens in the story’s present time, on a yawl (i.e., a cruising boat) that is floating down the River Thames just east of London. The yawl carries five people: a captain, a lawyer, an accountant, a man named Marlow, and the unnamed narrator. This first narrator sets the scene and frames the nested narrative that will comprise the bulk of the novella: that is, Marlow’s account of his harrowing journey into the heart of the Belgian Congo. Throughout the text, the reader is constantly reminded of this framing device due to the quotation marks that open each new paragraph, indicating that the frame narrator is recounting Marlow’s words. This strategy of using quotations creates the impression that Marlow is a disembodied voice, which is indeed how the frame narrator perceives him once night comes and Marlow speaks in total darkness. 

Marlow tells his story in a linear fashion. He begins with his search for work in England, his trip to Brussels to accept an assignment in the Belgian Congo, his journey down the Congo River in search of the mysterious Kurtz, and his return to Brussels. The major conflict in the novella plays out between Marlow and Kurtz, who for most of the story is present only by reputation or as imagined by Marlow. Although Marlow and Kurtz both champion the “civilizing mission” of empire, they differ in their evaluation of how that mission has been conducted. Where Kurtz sees meaningless brutality, Marlow sees absolute necessity. However, there is another, more metaphysical conflict: both Marlow and Kurtz confront the challenge of remaining their civilized European selves in the far-flung reaches of the world, where morality succumbs to savagery. As he cruises down the Congo, Marlow constantly hears Europeans praise Kurtz for his superior intellect and integrity, but when he reaches the Inner Station, Marlow finds that Kurtz has descended into an irrational and amoral state. Marlow, however, maintains his moral integrity and returns to Brussels to face Kurtz’s friends, family, and fiancée. 

In terms of form, Marlow’s story follows the structure known as “the hero’s journey,” in which a hero sets out on an adventure, faces a crisis, conquers it, and returns home transformed by the victory. Homer’s Odyssey provides a touchstone example of the hero’s journey. Although Marlow’s journey into the “heart of darkness” resembles a prototypical hero’s journey, his proves slightly more complicated in the sense that the crisis he faces is twofold. On the one hand, he must strive to stay true to his values despite the brutality he witnesses. On the other hand, he must come to terms with the madness and savagery he witnesses in Kurtz. Marlow gets through the first aspect of this crisis, in the sense that he conquers a grave illness and the terrors he witnesses and returns to Europe without breaking down mentally. Unlike the prototypical hero, however, Marlow never vanquishes his enemy, Kurtz, who expires on the return journey. Marlow feels haunted by Kurtz’s death, and he continues to carry the burden of this mysterious man into the present moment. Marlow’s journey is thus not transformative in the traditional sense; he returns home haunted instead of victorious, making Heart of Darkness a decidedly antiheroic tale. 

Although Marlow’s story concludes on an antiheroic note, the ending of the novella is not exactly tragic. After all, Marlow returns home safely, having survived a physically and psychologically challenging journey. He is not left destitute, nor is he struck down by some catastrophe or misfortune. That said, Marlow may triumph over unpleasant experiences and survive to tell the tale, but his journey does not conclude happily. For these reasons, Heart of Darkness could be said to have an ambivalent ending, meaning that it ends with mixed feelings. The ambivalence of the novella’s ending becomes clear when Marlow stops talking and becomes, in the frame narrator’s words, “indistinct and silent.” In the quiet that ensues, the mood that comes over Marlow’s audience is ponderous and heavy, much like the “sombre” river that flows under an “overcast” sky. Furthermore, instead of reflecting on Marlow’s tale and any lessons it might teach, the frame narrator sits in pensive silence with the rest of his companions. It is here that Conrad chooses to end his novella, frustrating the expectation of a clear sense of conclusion.