After the Clearing's destroyed in a dinosaur attack, the Survivors must find a new home. Gavin discovers a clue about where Eve has been taken, but tracking the lead down results in even more tragic consequences.

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 BC. Josh and Riley wake up in an unfamiliar time.

After an emotional reunion, Gavin and Eve attempt a daring escape from their unforgiving captors; Lucas leads a dangerous mission to the fort to reclaim the resources his friends so desperately need.

When their plan to infiltrate the Building goes awry, Gavin finds himself 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. In 1988, Josh and Riley enjoy some fun before a startling turn.

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.

When a fog falls over the Clearing, Eve leads a defense against a group of invaders, only to encounter a threat more dangerous than they’ve faced before. In 1988, Josh and Riley pursue a woman who may hold the key to stopping the impending tidal wave disaster.

Eve, Gavin and others attempt to commandeer a shipment of black rock to gain access to the mysterious Building, where they believe they may find a way to bring Josh and Riley home. In 1988, Josh and Riley must act swiftly to prevent Caroline from altering the timeline.

A reunited Harris family leads the effort to rescue Caroline and stop the sinkholes from happening, only to face forces that threaten to tear their family apart. With Lucas' life on the line, Ty accepts a challenge to win his friend a cure.

When a Survivor is murdered, Lucas and Sam lead a contentious investigation to find the killer. Gavin embarks on a mission to save Eve from the fateful vision he’s had of her death. Eve finds herself closer than ever to seeing it come true.

A ruthless enemy holds the Clearing captive, threatening to kill a beloved Survivor if their demands for an unexpected item aren't met. Gavin and Sam lead the rescue attempt, aided by an old friend whose return holds more questions than answers.

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.

The Harrises return to 10,000 BC, determined to upload a virus that will stop all sinkholes, despite knowing that this will mean they will never get home again. An unlikely leader rallies the Clearing to face an oncoming prehistoric threat.

Eve and Gavin ally with James to infiltrate the Lazarus Building in hopes of saving Ty and stopping Kiera from destroying their only way home. When a deadly horde awakens beneath the Clearing, Veronica must save Ella before a lethal sting kills her.

Gavin leads his family toward a new way home, but each step inches everyone closer toward his devastating vision of Eve's death. Levi, ostracized from the others, is given a chance at redemption when an old foe proposes a deal.

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.

While Gavin enlists the help of his grandfather 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 suspicious man who reveals information about the mystery behind the sinkholes.

As the Survivors attempt to integrate with the villagers at the Fort, a flock of vicious pterodactyls attacks. Ty tries to figure out his next steps and seeks help from an old friend.

When a massive fire breaks out, forcing everyone to flee, Sam and Lucas lead the group's fight for survival. Gavin is kidnapped by a woman with a surprising connection to his old life who may hold the answers about Eve that he's been seeking.

Gavin leads the survivors in trying to find Eve, Josh and Riley. Will he be able to finally reunite his family and still find a way back to the lives they once knew?

With Josh’s life on the line, Eve traverses the dangerous wilderness back to the clearing to save him. Desperate to kickstart a rescue mission, Gavin and Izzy work to prove there are survivors alive inside the sinkhole as government agents track their every move.

As Gavin and Sam search for a secret military base, they're surprised by an old colleague of Gavin's who just may hold the clues to finding Eve. When Ty and Sam try to figure out how to bring their friends home, Ty becomes sidetracked as he confronts his demons from his past.

With cold weather approaching, Eve, Levi and Ty return to the fort, despite their near-death experience there, hoping to learn 10,000 B.C. survival skills. Gavin's attempts to spare Izzy pain threatens their relationship.

A traitor turning on the Survivors leads to a deadly confrontation as they're shocked to learn where Eve has been taken.

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.