"Happily Ever After" is an orchestral piece from the Season 6 soundtrack. It plays at the end of the episode of the same name.
Having just awoken, Desmond asks Penny out to coffee. She accepts. Happy, Desmond leaves the stadium and returns to his car. His driver again offers to do "anything" for him, and this time, Desmond has a request - the Oceanic Flight 815 manifest. He wants to find the passengers so he can "show them something".