You don’t know from the get-go if this is an allegorical story or a literal one or something else. And I am not spoiling it for you here.  TBTB&TB was a deceptively simple book to read.  While a readers ability level need not be high to enjoy the book, the story does eventually give way to darker and very realistic elements.  This is about a young boy stranded both emotionally, physically, and metaphysically.  Dissecting these issues of loss and abandonment should be tackled with appropriate students.   If you are looking for a short but intense book that can appeal to a wide range of reading skills, this might be the book for you.