Final answer:
The question appears to explore the use of vivid descriptions in literature to advance the plot and build narrative tension, with some confusion regarding authors. The excerpts focus on a range of emotions, from innocence to terror, often with nature as a thematic element.
Step-by-step explanation:
The query provided pertains to the vivid descriptions that move the plot forward in certain literary works, possibly as part of a question or an analysis about the storytelling techniques in literature. While the mention of Twain suggests a focus on Mark Twain's writing, the text includes descriptions suggesting a sense of danger, grief, terror, or the innocence of nature, as seen in the excerpts. It's noteworthy that the description mentioning Twain seems to be an error, as the book 'To Kill a Mockingbird' is authored by Harper Lee, not Mark Twain.
A common theme in the provided excerpts is the vivid description of events and how these descriptions contribute to the plot, character development, or the overall atmosphere of the narrative. The passages emphasize the sense of peril, the contrast between innocence and danger, and the use of nature as a backdrop to human experiences. The stories reflect on intense emotions and the unpredictability of life through these vivid descriptions.