Mark Lee

Desperate to reunite with her son, Eve follows a lead that brings her face-to-face with a ruthless prehistoric group; Gavin, Izzy and Ella question whether they're fit to survive in 10,000 B.C.; Josh and Riley wake up in an unfamiliar time.

Gavin enlists his grandfather's help to guide him to his missing wife; Eve and Levi navigate a horrifying new reality; in 1988, Josh and Riley discover they're being followed by a man who reveals information about the mystery behind the sinkholes.

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.

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.

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.

When the clearing and fort unite to celebrate the union of Ty and Paara, the invitation of a controversial guest threatens to upend the festivities. Lucas offers Veronica an unexpected strategy to unravel her captor's odd connection to 10,000 BC.