"Darkness of the Heart" is a work by the famous English writer Joseph Conrad, which reveals the theme of colonialism and delves into the psychological aspects of human nature. The main character, Marlo, travels down the Congo River, which becomes a symbol of darkness both in the outer and inner worlds. This book reflects on the border between good and evil, on the human capacity for cruelty and knowledge of one's own essence. The interweaving of internal conflict and external reality create a dizzying image of reality, which prompts the reader to think deeply about the nature of the human soul and its capacity for evil secrets.