All ten episodes from the first season of the science fiction drama. When a sinkhole appears in Los Angeles at the site of the La Brea Tar Pits, people, buildings and vehicles are quickly swallowed up. While the survivors try to piece together what happened, they discover that they are stuck in a primeval land and must work together if they want to survive. The episodes are: 'Pilot', 'Day Two', 'The Hunt', 'The New Arrival', 'The Fort', 'The Way Home', 'The Storm', 'Origins', 'Father and Son' and 'Topanga'.