Professor Nick Cutter's wife Helen disappeared eight years ago. When his student Connor Temple tells him of a strange creature sighted in the place of her disappearance he goes there to investigate.
Another anomaly opens in the London Underground, this time leading to the carboniferous period. When the team arrive they deal with giant arachnids but a more dangerous creature hides in the shadows.
Cutter and his team are called in to locate a giant marine reptile that ate a lifeguard at a swimming pool. When the remains of a special forces diver are sent back through the anomaly, Cutter suspects his wife Helen is on the other side.
Helen warns Nick of an anomaly at a football stadium. When the team arrive a group of infected dodos come pouring through. Meanwhile Connor's friends Tom and Duncan decide to follow Connor to see what he's up to.
When a golfer at a hotel's golf course goes missing, Cutter and his team are called in. They find a giant pteranodon that's flown through an anomaly in the sky but Nick isn't convinced the creature is the culprit.
Missing people at Wellington Zoo could be the work of a new creature that came from the future. Helen reappears offering to help but Lester and Claudia are suspicious of her true intentions.
Cutter grapples with Claudia's disappearance after he returns to a very different present than the one he left. Soon after, the team are called in to capture a pack of raptors on the loose at a local shopping center.
An anomaly to a period before an oxygen-based atmosphere appears on the 15th floor of an office tower, filling it with fog and gigantic worms. New team member Jenny Lewis comes to terms with the dangers of her new job.
An outdoor adventure park is terrorized by a hungry saber-tooth tiger. Cutter and his team try to track down the beast but Valerie, a skeptical staff member stands in their way.
The new anomaly detector detects an anomaly in the River Thames, where Abby is taken by one of the creatures. As tensions rise amongst the team, Cutter and Connor set out to rescue Abby.
A young girl chases her dog through an anomaly into a bleak, sandy landscape filled with burrowing monsters. Cutter and Stephen go through to rescue her but when the anomaly closes, the three of them are stranded with no apparent way home.
As the rest of the team capture a Columbian Mammoth running rampant on the M25, Stephen allies himself with Helen. The traitor is finally revealed as they attempt to kill Lester and destroy the ARC from within.
With the ARC team held captive Stephen reluctantly helps Lester capture a Silurian Scorpion let loose on a popular beach. The conspiracy unravels and people working closely on the project die -- or do they?