"Dave" is the 43rd episode of Lost and the 18th episode of the second season. The episode was directed by Jack Bender, and written by Edward Kitsis and Adam Horowitz. It first aired on April 5, 2006, on ABC. In flashbacks, Hugo "Hurley" Reyes is in a mental institution, where he deals with an imaginary friend, Dave. Libby also has a brief flashback in this episode, revealing that she attended the institution along with Hurley.