Wormholes cause trouble on moving day. Or is moving day causing trouble with wormholes? While Jack tries to fix the wormholes Fargo is determined to something about moving day.

The Smart Dust control unit is still on the fritz and wreaking havoc on the town's communications systems. The bio-printer has gone missing and Holly (Felicia Day) is definitely not herself.

When Grace's spying is revealed, mistrust is in the air. Major Shaw shows up to take control of the situation just as a geo-engineering project cuts off communications to the outside world.

Jack's idea of a romantic honeymoon doesn't quite mesh with Allison's. Holly tries on her new body. Jo and Andy followup on an investigation begun by Jack's predecessor.

Allison's also brilliant brother visits the newlyweds to give Jack a hard time but Jack's intellect rises to the occasion. Henry and Zane work on freeing Holly from her virtual reality cage while struggling just to keep her alive.

Eureka celebrates Feynman day with a plethora of practical jokes. While mostly harmless the jokes make it challenging to identify the real catastrophes Eureka is so prone too.

Fargo is convinced that Holly is still inside of the Matrix computer, but the DOD is determined to wipe its hard drive clean -- losing Dr. Marten forever.

A disaster simulation causes a disaster. Then another. And another. Fargo finds Holly in the computer.

With life back to normal, the Astraeus crew struggles to overcome their Matrix Eureka experience: what was real, what wasn't and what could become self-fulfilling prophecy.

The town comes together in a final attempt to locate the lost Astraeus.

Hours before the launch of the Titan mission Eureka struggles with black holes and, having decided who will stay and who will go, goodbyes.

Grace embraces an honor that strains her relationship with Henry while Deputy Andy becomes an accidental guinea pig for the Astraeus mission -- with catastrophic results.

As the Astraeus candidates undergo final interviews, Carter and Allison appeal the results of their relationship audit while trying to keep a lid on escalating mishaps around town.

The predicted danger posed by Allison materializes when she is subjected to mind control to steal Eureka's secrets.

Carter must solve an only-in-Eureka bank robbery before the town floats away, while Allison deals with unsettling episodes of lost time.

Carter and Jo try out Zane's new high-powered risk assessment system, but find that even it may not be a match for the dangerous level of competition among Eureka's scientists.

When Eurekans start behaving oddly, Carter scours the town for a cause - never suspecting that Allison, miles from home, is the one facing real danger.

Carter lands in an awkward situation after S.A.R.A.H. and Andy's nuptials hit a snag; Zane keeps harassing Jo for details; an unscheduled launch presents trouble for the gang.

Sheriff Carter relates a Christmas story in which the defensive field malfunctions trapping everyone in town for the holiday. So Fargo throws a big party, unaware that the town is shrinking. All from a quest for the perfect fruitcake.

As Grace (Tembi Locke) finds a way to share her memories with Henry (Joe Morton), the rest of Eureka's citizens face the return of people from the recent - or not so recent - past.

Allison accepts Carter's offer to include Kevin in a camping trip for some guy time, and Henry decides to level with Grace while a very peculiar -- and dangerous -- relationship threatens Eureka and the not-so-happy campers.

Allison deals with a major problem during Eureka's space week festival.

Wil Wheaton guest stars as Dr. Isaac Parrish, an underappreciated scientist whose hostility appears to have gone viral. Blind rage is infecting everyone at Global Dynamics with potentially catastrophic results -- especially for Fargo.

The gang returns from 1947 and discover that things are not as they remember them. And Dr. Grant came along.

During the Founder's Day celebration, Jack, Allison, Fargo, Henry, and Jo somehow end up in 1947, in the middle of the army base that existed before Eureka was founded. They must find a way home before they change history or get caught.

Carter deals with a new magnetic force tearing apart the town, Zoe gets unexpected news about her college application and Tess drops a bombshell about a job offer.

An immense ice core from Russia threatens to turn Eureka into a giant ice cube and the residents into icicles.

Jack and Allison chase Douglas out of the Eureka lab because it is about to be sterilized. Making their escape a little more difficult, the town has come down with a plague of amnesia.

Jack, Henry, and the rest of the GD team try to figure out why teenagers are building towers out of junk, the signal moves closer faster, and Fargo's old car doesn't like being dumped.

A bowling tournament brings a rival team from Area 51 to town, but when a practical joke goes too far Jack may be the town's only hope for survival. Meanwhile, Lexi is not happy when Duncan returns.

Carter finds out more than he bargained for when he's trapped in an alternate dimension with the new scientist. Meanwhile, the father of Lexi's babies comes to town.

Jo displays atypical behavior after a DNA scan malfunctions, unfortunately it's while she's interim sheriff when Carter is required to undergo a 48-hour DOD recertification test.

Sheriff Carter interviews for a new job, Zoe braces herself for change, and someone works behind the scenes to make sure the new sheriff, a robot, fails.

All of Eva Thorne's secrets are revealed when she pushes for early destruction of the bunker. Zoe begins to experience the effect of the substance in which she slipped, leaving Carter to risk his life and job in order to save her.

The appearance of a second sun makes election week in Eureka a little more intense, and gives Eva Thorne an opening that may mean the end of Global Dynamics.

While Jack keeps having to rescue Lexi from a bumbling superhero, Zoe gets trapped while exploring an abandoned facility under the high school with her friends.

An opened sarcophagus unleashes a plague onto those who opened the tomb, and when it threatens Eureka, Carter has to devise a temperate fix. Meanwhile, Allison thinks she's gong crazy when she keeps seeing Nathan.

It's Allison's wedding day, and Carter is stuck in a time loop that causes him to relive it over and over. Unfortunately, there's no simple act that will right things, and the solution may prove very costly.

Carter is frustrated when he's told to investigate when robotic dogs begin exploding, believing it's a waste of his time. He's even more frustrated when no one else feels the earthquakes he's experiencing.

Carter and Allison search for a missing man in a bio-dome while Eva Thorne makes changes in town in the name of balance and efficiency.

The D.O.D. has sent in a business shark to perform an evaluation of Global Dynamics' viability, and everything that could possibly go wrong, does. Including a drone, whose boosted AI turns it into a killing machine.

A flesh eating virus has infected Global Dynamics, and the building goes into a security protocol that endangers everyone's lives.

The town's metals begin to spontaneously turn to gold, but the wealth may be as fleeting as the town when the structures begin deteriorating.

All the women of Eureka begin to pursue Carter, so something must be very wrong.

Zoe and her friends lose their voices, but whatever is causing the symptoms has an even worse effect on Allison and her only hope comes from an unusual source.

Carter begins to disappear on his anniversary, Zoe is stuck with another student for a school project, and Henry and Nathan examine the item Henry found.

When Allison puts a newly hired, but criminal, genius in Jack's care he's less than pleased, but then an accident in a lab causes most of GD to lose their smarts, and he may be the only one with the solution.

Fargo's grandfather is discovered in a cryo-stasis chamber, but no one can determine how he got in there. Elsewhere, Zoe pursues another mystery involving her dad and a dozen roses.

Groups of people begin sharing dreams in some embarrassing and conflicting ways as a result of some accident of convolutedly blended pairing of technologies and havoc ensues.

Debris starts raining down on Eureka on the day of the school's science fair, and there may be a connection to Zoe.

The people of Eureka start disappearing, and Jack is the only one who notices.

A surprise visitor throws Jack disrupts his and Zoe's lives; strange weather must be tracked to its source before it becomes an "ice funnel of death."

When Fargo activates a mysterious device on Allison's first day, he endangers not only himself, but Global Dynamics and Eureka as well.

Henry and Jack struggle to deal with their losses as people begin burning to death for no apparent reason. At Global, Stark awaits the decision of the DOD.

After another lab accident Jack wakens to a whole new world.

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).

Strange behavior exhibited by the townspeople is investigated by Carter,who has to solve the mystery before Stark makes a decision that could affect the world.

Taggart achieves a medical breakthrough while Fargo invents a device that bridges the divide between computers and human brains.

Odd fluctuations in computer-controlled environments may have something to do with the return of Eureka's prodigal son.

A car accident leads back to scientists at Global, Zoe finds a boyfriend, and Jack tries to drum up support for a town baseball league.

After Fargo triggers a device from the Cold War era, the race is on to shut it off before it starts a world war, but the only solution may lie in the depths of a demented scientist's mind.

A lab accident causes a scientist to, seemingly, become indestructible, but Carter and Stark have their own concerns.

The presence of a crop circle leads to thoughts of an alien invasion, the future of Eureka is threatened when a congressman visits, and Jo and Jack work on their trust issues.

Occurrences of short-term memory loss begin when visiting scientists hit town, and Jack has to determine the cause while not letting down Zoe who is acting in a school play.

What appears to be a ghost begins terrorizing people and disrupting equipment shortly after a funeral, and even more surprising, one of the recently dead reappears alive.

After a strange accident sidelines Eureka's sheriff, U.S. Marshal Jack Carter takes over the investigation into the mysterious phenomenon that led to the death of a resident.