Wow, great atmosphere and descriptions! You depict the hopelessness of the situation well. I also like how you incorporated the theme.
You might want to try shortening your sentences, though. Some of them were really difficult to parse, with lots of clauses all chained together. For example, the fifth paragraph (starting with "The skirmish of the night..." is only two sentences long, but the sentences are quite complex. And toward the end of the seventh paragraph, you have a sentence with "The mirror that reflected the light that carried the messages..." This kind of nested construct can be difficult to parse.
But again--great atmosphere! I was not expecting where you took the story, and it was really delightful.