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 the survivors' food supply dwindling, Eve and Ty venture into the forest on a risky hunting expedition only to face unexpected dangers that threaten their survival. 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 with whom he shares a complicated past.