A commercial airliner flying from Sydney to Los Angeles breaks apart in mid-air and is strewn across a seemingly deserted tropical island in the South Pacific, with forty-eight survivors of the initial crash. Mysterious roars are heard from the jungle and trees are found knocked over. Jack, Kate and Charlie set out into the jungle so they can send out a distress signal using the planes transceiver. They also find the co-pilot, who survived the crash, but is soon killed by the mysterious "monster". A flashback shows Jack on the plane.