 SPOILER: One of the key questions with the character Walt is casting  and problems that arise concerning the proposed time line on the  show. While the series moves slowly through time and only weeks have  passed on the show, the actual filming has stretched over two years.  When originally cast, Walt was portrayed as a 10 year old boy but,  after two seasons, he no longer looks 10. The shows writers appear  to have dealt with this at the end of season two, by sending Michael  and Walt away from the island toward supposed rescue.