Tonantzin Carmelo

The team investigates the death of a famed Marine commander's son, while a pivotal part of Franks' past involving his family is revealed.

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.

With cold weather fast approaching, Eve, Levi and Ty return to the mysterious fort despite their near-death experience there in the hopes they might share their 10,000 BC 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 for thwarting their way home, desperately tries to make amends by leading the effort to dig them out. Gavin embarks on a journey into his past, which could provide a crucial piece to saving his family in the present.

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.