Things have changed at the ARC. Connor and Abby are still missing in the Cretaceous, and Danny is stranded in his search for Helen. In their absence, a new ARC team springs into action. The new ultra-efficient operation descends into disarray, however, when the Dracorex escapes from the menagerie.

After a year in the Cretaceous, Abby and Connor finally escape through an anomaly ... only to be followed through by a giant Spinosaurus. Becker, along with new field leader Matt, attempt to corral the creature back through the anomaly during a high octane chase. In the end, Connor inadvertently saves the day.

Unfortunately, new boss Philip informs Connor and Abby that they are no longer needed. Will things ever be the same again?

Meanwhile, Matt meets mysterious stranger, who seems to know all about the ARC operation. Is there more to Matt than meets the eye?

When Connor looks up old friends Duncan, he doesn't expect to find him obsessed with creature sightings. Warning him of the elusive dock creature, the pair tracks it down—only to find evidence of a fresh kill. With Abby and Matt arriving to help, they find the creature after a tense chase through a container yard.

Will Connor's quick-thinking and bravery earn him back his place on the team?

A mysterious group come through an anomaly in a theatre, unknowingly followed by deadly tree creatures. As they attempt to escape, Matt inadvertently brings one of the group—Emily—back against her will. She promises to help him find the creature, in return for going back through the anomaly. In a frantic chase through the city, they track the creature down, only to discover the anomaly has closed, leaving Emily stranded.

Saturday detention is thrown into disarray when a deadly Therocephalian attacks a teacher, allowing the kids to run amok. The team is soon faced with not only tracking down the creatures, but fighting against the antics of the terrified students. Finding a Therocephalian nest in the school cafeteria, Connor enlists the help of the kids to stun the creatures into submission before returning them through the anomaly.

Sent to investigate an odd anomaly signal, Connor and Abby uncover the existence of a supposedly mythical Labyrinthodont in a small coastal town. In tracking it down, they come across dangerous fuel-smuggling farmers who put their lives at risk. Back at the ARC, Matt is concerned about Emily's disappearance, and sets out to find her.

While investigating an anomaly at a stately home, the team stumbles across a wedding—of ex-ARC member Jenny Lewis. When Matt and Emily inadvertently let a savage Hyaenadon through an open anomaly, Connor becomes trapped in the cellar with its pups. As the creatures run amok, Jenny can't help but fall back into ARC mode, as they return the creatures and restore order to the wedding.

When a Terror bird appears during an incursion, the team faces an anomaly that won't lock. Chaos ensues, as a terrified creature struggles to get home. Danny reappears from his journey through the Rift Valley with a warning for the team and suspicions about their new boss. Ethan's secrets are finally revealed as he takes his revenge on Emily and the team.