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.

Eve, Levi and the rest of the search party explore a mysterious fort that raises more questions than answers. With the help of a new ally, Gavin and Izzy embark on a dangerous and unauthorized mission to save their family despite government warnings that they could cause unprecedented disaster.