Conrad plays with the duality of human nature by using the dichotomy of light and dark imagery. He juxtaposes the two images and colors together to show the intense proximity between the two. Kurtz, a man who has been admired and revered by the Company members at the Outer Station, becomes consumed by the darkness in the Inner Station. These two Stations represent the progression towards evil.
Conrad also adds a gothic and supernatural tone to his novel by using fog and smoke as symbols of confusion and mystery. The continuous fog that follows Marlow’s ship on his journey gets thicker as he progresses towards the Inner Station where Kurtz is. This fog represents the lack of clarity and control the members of the Company hold. As the ship gets closer into the heart of the indigenous country, morals, ethics, and humanity dissolves into this fog and the person is left consumed by the greedy nature to their task. The nature of war and authority clouded their minds of their goal and brought about this darkness and haze.
Colonialism becomes a foggy idea, and the people included in it lose their sense of guidance. Conrad uses gothic imagery to express his views on the confusion and lost ideals of the Europeans. Conrad refers to Kurtz as the “nature of a supernatural being.” Kurtz exemplifies the ideal consequence of this fog and confusion. He does not talk in complete sentences and his thoughts are incoherent. He is the epitome of mystery and the haze behind colonialism.