The narrator in Joseph Conrad's "Heart of Darkness" expresses a sense of skepticism and disillusionment about a character he describes as a "papier-mache Mephistopheles." This metaphor suggests that the character is not genuine or substantial, presenting only a façade that lacks depth or true power. The imagery of being able to poke through him and find nothing but dirt underscores the emptiness and hollowness of this figure, indicating a broader commentary on the deceitful nature of appearances and the fragility of perceived authority.

This observation reflects the themes of illusion and reality prevalent throughout the novella. The notion of encountering something that appears menacing but is, in reality, insubstantial raises questions about the nature of evil and the tendency of individuals to be swayed by surface impressions. Conrad uses this moment to convey a sense of existential dread, illustrating how the darkness of human nature often lies beneath the superficial layers we encounter.