It has been my experience that in literature, the first paragraph and the last paragraph often provide thematic windows onto the text as a whole.  Consider the very first sentence of the story: “It unrolled slowly, forced to show its colors, curling and snapping back whenever one of us turned loose.”  Although the narrator is referring to a map, the details also say much about the men and their experiences on their trip:  they themselves “unroll,” each show his “colors,” and each also “curls and snaps” when the rules of life as they had previously known them “turn loose.”  Consider the irony of this line further into the story:  “From where we were the cliff looked something like a gigantic drive-in movie screen waiting for an epic film to begin.  I listened for interim music, glancing now and again up the pale curved stone for Victor Mature’s stupendous image, wondering where it would appear, or if the whole thing were now not already playing, and I had not yet managed to put it together” (147).  I quote from the Delta edition.