Police raid the Shannon home and arrest father of three, Jim Shannon. Shannon realizes he must take drastic measures to keep his family together after his wife, Elisabeth, is selected to travel back to prehistoric times to create a new civilization and, hopefully, help change the future.

Police raid the Shannon home and arrest father of three, Jim Shannon. Shannon realizes he must take drastic measures to keep his family together after his wife, Elisabeth, is selected to travel back to prehistoric times to create a new civilization and, hopefully, help change the future.

When Terra Nova comes under attack from a legion of Pterosaurs, Jim and Taylor must find a way to save the colony before it's completely overtaken. Elisabeth discovers a former flame is also living in Terra Nova and may have been responsible for her recruitment. Syke tries to make Josh feel at home and Reynolds get protective of Maddy.

When Elisabeth, Jim, Malcolm and Taylor investigate radio silence at a nearby scientific outpost, they discover an outbreak of a mysterious virus causing memory loss, paranoia and eventually passing. The group must work together to find a cure before they lose their sanity and all of Terra Nova is infected.

When an orphaned Sixer runs away and shows up at Terra Nova looking for help, Shannon and Taylor disagree about whether she can be trusted. Taylor suspects that someone in the camp is a traitor. Meanwhile, Reynolds admits he has feelings for Maddy.

The colony falls victim to its first cuddle, and Jim and Taylor must find the perpetrator. Also, Skye helps Josh find a way to get Kira, his girlfriend from 2149, to the past, while Elisabeth and Zoe race to help an unborn Ankylosaurus survive.

All of Terra Nova's technology is wiped out after a meteor crashes. Maddy and Reynolds get stuck outside the walls. Skye and Elisabeth team up to save someone's life. Mira and the Sixers try to attack and Taylor must stop them.

Maddy's life is in danger when she finds out a secret about one of Terra Nova's top scientist. Josh makes a deal to bring Kira back from 2149, but this could be trouble.

Taylor looks for the Sixer mole that Mira sent into Terra Nova. Jim looks into an old cuddle, for which it looks like Taylor might be guilty.

Taylor and Mira confront each other in the jungle as he learns more about her plans and about his son. However, they must work together to battle a prehistoric enemy. Jim gets close to discovering the identity of the Sixer mole and Terra Nova is locked down.

Lucas races to assemble the final pieces of his mystery device, in advance of the 11th Pilgrimage's arrival. Also, Jim and Taylor confront the colony's "Sixer" mole, Skye is reunited with a familiar face and Terra Nova prepares for war.

In part one of the two-part season finale, the 11th pilgrimage arrives. With the assistance of Lucas and Mira, the Phoenix Group tries to pillage resources from Terra Nova.

In the second part of the two-part season finale, Jim and Taylor fight against the Phoenix Group. A major decision is made regarding the future of Terra Nova after a colonist is forced to make the ultimate sacrifice.