The quote from Joseph Conrad's "Heart of Darkness" evokes a vivid image of a vast, imposing jungle that looms darkly at the boundary between land and sea. The description of the jungle as "colossal" and "dark-green" creates a sense of foreboding and mystery, suggesting both beauty and danger within its depths. The contrast with the white surf adds to the visual imagery, drawing the reader's eye along a defined line where nature's elements meet.

The "blue sea," described as glittering but blurred by mist, enhances this sense of an enigmatic landscape. The creeping mist symbolizes uncertainty, obscuring what lies beyond the immediate view. Combined, these elements set the stage for an exploration of the darkness that lies not just in the jungle, but within the hearts of men, which is a central theme in the narrative of the story.