Mark Lee

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 unauthorised mission to save their family despite government warnings.

With Gavin on the verge of dying, Eve and her family make a desperate attempt to set things right -- even as an unexpected twist threatens to tear them apart forever; Veronica reveals a secret that sends her relationship with Lucas into jeopardy.

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.

When a stunning revelation puts Josh and Izzy's lives on the line, Eve and the other survivors desperately search for the young boy who holds the key to saving them; Gavin and Izzy must rely on a stranger if there is any hope to reunite their family.

With news of one last sinkhole opening, Gavin, Izzy and Dr. Nathan race to Seattle to launch a final rescue effort before it's too late; Eve embarks on a perilous journey to send a young boy though a portal in order to save her family.

When plans to infiltrate the building go awry, Gavin comes face-to-face with its enigmatic leader; Eve, Levi, Sam and Izzy are forced to rely on a former adversary to lead a rescue attempt; Josh and Riley enjoy some fun before a startling turn.