Season 2 had 23 episodes and were shown in the United States and Canada on Wednesdays starting September 21, 2005. Most of the story is about the conflict between the survivors and the Others. The survivors go down into the hatch door and find a secret, underground building where a man named Desmond has been living for three years. They learn about the DHARMA Initiative, a group of scientists who built the hatch and many other buildings on the island. The characters meet a new group of survivors from the tail end of the crashed airplane. One of the crash survivors betrays the other castaways by working with the Others.