Lost season 6 episode 4 s06e04 The Substitute. The suspense, drama, and action in the television series Lost have been the factor why it captures the hearts of viewers not only in the United States but around the world. It is one of the most watched and most loved television series . Lost season 6 episode 4 will be air at February 16, 2010 and Lost season 6 episode 4 entitle to "The Substitute".