The novella also explores the blurring of lines between civilization and savagery. Marlow, who begins his journey as a civilized and rational European, gradually becomes more and more drawn into the darkness of the Congo. As he journeys deeper into the heart of Africa, he encounters various European characters who have abandoned their civilized values and succumbed to the savagery of the environment. The character of the Russian harpooneer, for example, serves as a symbol of the European who has gone native, embracing the savagery and brutality of the African environment.