Virginie Laverdure

When a massive sinkhole opens in Los Angeles, the Harris family is split in two; Eve and her son are sent to a mysterious primeval world; Gavin discovers that the visions that have plagued him for years might hold the key to bringing them home.

With Josh's life on the line, Eve traverses the dangerous wilderness back to the clearing to save him; desperate to kickstart a rescue mission, Gavin and Izzy work to prove survivors are alive inside the sinkhole as government agents track them.

With cold weather approaching, Eve, Levi and Ty return to the fort, despite their near-death experience there, hoping to learn 10,000 B.C. survival skills; Gavin's attempts to spare Izzy pain threaten to do their relationship more harm than good.

When a chaotic superstorm hits the clearing, a structural collapse puts Marybeth and Lucas' lives in danger; Eve, still at odds with everyone, tries to make amends by leading the effort to dig them out; Gavin embarks on a journey into his past.

With time running out before their window home closes, the survivors hatch a final escape attempt, but that plan is put into question when they receive a stark warning from Gavin that it will end in disaster, forcing Eve to make an impossible choice.

With the survivors' food supply dwindling, Eve and Ty venture into the forest on a risky hunting expedition; as an unlikely rescue mission comes to fruition, Gavin must put his faith -- and the fate of his family -- in the hands of an old friend.