The series follows the experiences of the survivors of a plane crash on a passenger jet, Oceanic Flight 815, which crashed on a tropical island in the South Pacific, with each episode typically featuring action on the island as well as a secondary storyline from another point in a character's life. The series also includes stories of the lives of people already living on the island — they include the "Others", who initially antagonize the survivors, as well as a group of people who arrive on the freighter "Kahana". "" consists of thirteen original two- to three-minute clips referred to as "mobisodes" which were produced for cell phones and released between seasons three and four. Multiple former and recurring cast members made an appearance in the series finale.