The river in the story creates a sense of movement, but also of entrapment. Marlow is moving towards Kurtz, but he is also unable to escape the river's path. This fatalism is a key element of the book's mood. Readers looking to explore this theme often search for a Heart of Darkness PDF. The digital format allows you to easily track the recurring imagery of the river and the jungle. The story is a powerful meditation on destiny, free will, and the forces that shape our lives.