Dad’s callous violence toward Miles is a stark contrast to the behavior of Martin, who sacrificed his own safety and sustained a serious injury in order to protect Miles. Dad, it seems, has no instinctive drive to comfort his own son. Martin’s wounded leg is significant on several levels—it highlights Dad’s own unwillingness to protect Miles, viscerally represents Martin’s role as a responsible father figure, and serves as a reminder of nature’s impartiality toward human beings.