Take an extract of the sentences describing the natural environment in Paragons 14 to 20. Tell me what the use of the description of the environment here is.

One Step After Another was the beginning of a novel. The description of the natural environment created a tense atmosphere for the development of the story. In the 14th paragraph, the scene of nightfall was described." The sky slowly darkened, and the gray clouds pressed down low as if they could fall at any time." This sentence described the changes in the sky to create a depressing atmosphere, paving the way for the protagonist's encounter and predicament. In the 15th paragraph, the water flow of the stream was described." The clear river quietly flows and makes a faint rustling sound." This sentence shows the natural beauty of the stream by describing the water flow of the stream. At the same time, it also foreshadows the encounter between the protagonist and the puppy. In the 16th paragraph, the image of the puppy was described." A cute puppy with long furry ears and black and white fur." This sentence described the image of the puppy as a foreshadowing for the encounter between the protagonist and the puppy. In the 17th paragraph, the protagonist's experience was described." He felt like a person trapped in a maze, surrounded by darkness and no sense of direction." This sentence expressed the helplessness and confusion of the protagonist through the description of the protagonist's experience, paving the way for the protagonist to escape and find a way out. In the 18th paragraph, the protagonist's escape was described." He carefully walked toward the exit step by step under the faint starlight." This sentence expressed the protagonist's courage and determination by describing the protagonist's escape, paving the way for the protagonist's freedom. The 19th paragraph described the protagonist's search for a way out." He walked along the stream for a while and finally saw a flashing light. He knew that it was the exit." This sentence expressed the protagonist's patience and persistence by describing the protagonist's search for a way out, paving the way for the protagonist's freedom. To sum up, the description of the environment in the step-by-step steps played a foreshadowing role, preparing the development of the story for the readers to better understand the plot and the emotions of the characters.