Your story is interesting and, for the most part decently written.
You do, however, have a problem with usage of "who" and "whom." Try replacing "who" with "he" and "whom" with "him"; if the sentence no longer makes sense, you've used the wrong one; e.g. "whom sat" becomes "him sat" and is obviously incorrect, and so, "who" is the form you need.
Keep up the good work. I look forward to reading further chapters.