It's Founder's Day in Eureka and everyone is in the spirit of the celebration until Jack, Allison, Henry, Jo and Fargo are transported back to 1947 where they meet some familiar faces along the way. Will they be able to get back to 2010 or will they be stuck forever in 1947 where Eureka is not a town, but an Army base.

Wormholes randomly materialize around Eureka as the Department of Defense is set to shut the town.

The crew moves forward after an ordeal and Warren's visit adds to the pressure.

Ambition trumps common sense when Stark is given a chance to try out the Top-secret artifact. Once it's tested, Eureka warps into the future and ends up in 2010, where the town is different.

Fargo's grandfather awakens after 50 years in cryogenic suspension and accuses his rival of putting him there and stealing his work.

In the season finale - It's chaos in Eureka when an energy beam rips through main street but the Astraeus launch must go on...with or without Eureka intact.

The Astraeus crew returns to Eureka four years later and must adapt to a myriad of changes, including a more oppressive version of Deputy Andy.

Beverly Barlowe resurfaces in Eureka seeking Carter's help to free the Astraeus crew, and the rescue plan lands Carter in the crew's virtual world.

One of the Global Dynamics tanker trucks spills, potentially causing a change in everyone's sleep habits... In the course of the episode, we come to learn that Global Dynamics has developed a technology that enables them to distill six months of the town waste and by-products into one truck, an amount that would normally fill Lake Erie.

It's Allison and Stark's wedding day and Carter finds himself reliving it over and over. Meanwhile, Carter's sister, Lexi, visits the town.

Trust issues are produced by a scientific find, along with sinister results. Zoe's life is in jeopardy, and Eva Thorne knows what has caused the predicament.

As an experiment that will recreate the first moment of the origins of the universe, the Big Bang, goes terribly awry, the town’s geniuses turn into morons, leaving the fate of Eureka in the hand of Jack Carter and an antisocial young ubergenius.

Sheriff Jack Carter becomes absolutely irresistible to every woman in Eureka. But if he doesn't get his mojo under control, they might just eat him alive.

The Eureka mayoral race is overshadowed by the sudden arrival of a second sun, forcing Carter, Allison and Zane to investigate it more closely.

Eureka's teenagers who appear to have been manipulated while asleep, gathered in a field where they assembled a strange structure comprised of scrap metal and electronics.

Henry's ship returns causing Carter to fear it maybe linked to the town's deadly electrical anomalies.

When the 5 get back to their time, things are changed everywhere. As the Henry tries to fix the machine that transported them in the first place, Dr. Grant is making himself comfortable as he can. Jack is still trying to wrap his mind at the fact that he asked Tess something that she says yes to and the fact that the group's positions changed. As one thing leads to another, a twist happens and things get a little dicey.

Eureka's citizens face the return of people from the past; Global Dynamics tests a new device.

When Grant and Carter become stranded, they must race back in time to save Eureka.

The town huddles in a last attempt to locate the vanished Astraeus before it's too late!

A bad day in the lab forces Carter to rethink his decision to live in Eureka, prompting an intervention from S.A.R.A.H. (the self Activated Residential Automated Habitat.

Nathan Stark and Jack Carter must put aside their rivalry to stop a deadly bacteria from destroying the town and killing Allison’s son. But can Carter ignore Stark’s crimes, as well?

Carter interviews for a job with the Department of Homeland Security, after being terminated as the sheriff. Deputy Lupo decides to resign after discovering that a very personable robot is the new sheriff.

Dr. Tess Fontana reopens Section 5, causing objects to become ambulatory , possibly due to poltergeists.

Tess has a job offer from Australia, Zoe is prepared to leave for Harvard and Carter has a magnetic disturbance above Eureka to contend with, in the third season finale.