Conrad masterfully exposes the brutal reality of European colonialism in Africa. The narrative does not shy away from depicting the exploitation, violence, and racism inflicted upon the native population in the name of progress and profit. The Congo, once a place of natural beauty and ancient cultures, is scarred and broken by the greed of the colonizers.

Through the character of Kurtz, initially presented as a brilliant and ambitious individual, Conrad explores the potential for darkness within every human heart. Kurtz's descent into savagery, mirroring the brutality he witnesses and perpetuates, serves as a chilling reminder of how easily civilization can be stripped away, revealing the primal instincts lurking beneath the surface.

'Heart of Darkness' is framed as a story within a story, with Marlow recounting his experiences to a group of men aboard a ship on the Thames. This technique highlights the importance of perspective and how stories shape our understanding of ourselves and the world around us. It also forces the reader to question the reliability of Marlow's narration, adding layers of complexity to the novella.