When a massive sinkhole mysteriously opens in Los Angeles, it tears a family in half, separating mother and son from father and daughter. When part of the family find themselves in an unexplainable primeval world, alongside a disparate group of strangers, they must work to survive and uncover the mystery of where they are and if there is a way back home.
If you saw the future would you change it? That's the dilemma facing Detective Inspector Rebecca Flint (Tamzin Outhwaite) and astrophysicist Dr Christian King (Emun Elliott) who've seen the disastrous events awaiting the world.