Eureka

When the ship with the Astraeus crew returns to earth, its occupants discover that four years have elapsed and time isn't the only thing that has changed.

After Senator Wen calls off the search, Kevin designs a tool to find the Astraeus ship, which is still missing after four months. Unfortunately, the device's assembly stops after Andy and Carter are arrested while stealing a component for it. Elsewhere, Jo's walkabout is rocky, and at the Astraeus crew's location Dr. Marten posits a dangerous theory about their situation.

Carter and Jo continue their search for the missing Astraeus crew. A surprising source confirms the new theory of the disaster, and offers to help them rescue the crew. Meanwhile, back at the lab, lives are at risk as more of the crew comes closer to the truth of their situation, and Carter is sent in on what may be a one way virtual rescue mission.

The Astraeus crew members attempt to overcome their experiences in the matrix; Fargo deals with Holly's death, Grace struggles to maintain her relationship with Henry, and Allison fights her feelings about Jo as they share Carter's house. This all fades to background noise, however, when Dr. Parrish's latest project is accidentally released and threatens to ignite the whole town.

Carter starts to swap bodies uncontrollably, which puts both his body and his consciousness in awkward situations. Meanwhile, Warren Hughes returns to GD. This time to evaluate Astraeus crew members' reactions to their abductions and any effect to their job performances. But Carter's body swapping jeopardizes jobs, relationships and, ultimately, his own life. Elsewhere, Zane's quest for answers from the matrix reveals disturbing results for both him and Fargo.

It's disaster drill day at GD and everyone must participate in order to see how well they would do in a disaster. Unfortunately the computer conducting the drill makes the simulation a reality. Elsewhere, Fargo undergoes risky interfaces with the matrix to confirm Zane's findings.

The Department of Defense insists on installing new security and removing all Astraeus artifacts, but Fargo resists because he believes Holly is alive in the matrix. Elsewhere, Henry recruits Carter for a brain experiment.

Carter and Allison's romantic plans run afoul of a rogue submarine, and it's up to Jo to save their lives … if she can fix the mess at Global Dynamics caused by an out-of-control prankster in time.

While under the influence of a smart drug, Carter becomes a genius like everyone else in town and starts to change the laws of physics. Unfortunately, his condition soon endangers all of Eureka, including Allison's brother who is in town just to meet his new brother-in-law.

Carter and Allison's perfect honeymoon is interrupted when sabotage is discovered in Eureka. Elsewhere, Holly faces another hurdle to remain intact.

The Department of Justice arrives to investigate Grace, and Henry struggles with his conscience. Holly receives a message that triggers a chain of events. The question is whether it's her actions or Fargo's malfunctioning signature achievement that are causing the scary incidents all over GD and the town.

The doubles steadily take over GD, which means Fargo, Allison and Zane are in a fight for their lives and everyone else's as they try to avoid capture and fix the problem.

In the series finale, the Department of Defense's closure of Eureka is delayed by random wormhole materializations.

The 60th anniversary of Eureka becomes life changing in more ways than one when a marriage proposal is eclipsed by a mysterious transport to a military site and a new face in the crowd.

As the Founders' Day festivities continue, Carter and the others must accustom themselves to the new time line and how Dr. Grant fits into it. Unfortunately, reacclimatization needs to occur on a steep learning curve. "Tiny", one of Global Dynamic's projects, has run amok in the crowded town.

Dr. Isaac Parrish, the brilliant director of the Non-lethal Weapons Lab, is feeling a little undervalued these days. Then all his latent hostility goes viral, infecting everyone with such fury that no one is safe, especially Fargo.

As Eureka celebrates Space Week, Dr. Ramsey unveils his cutting edge invention that could allow colonization of Mars. Unfortunately, a slight malfunction may cause it to incinerate Eureka before the dream is realized. Equally bad is that Eureka's go-to guy for crisis intervention has just gone to Boston to visit his daughter at Harvard.

Claudia Donovan visits Eureka to see if Fargo's promises of wondrous devices are true, but she finds herself in the middle of a mystery suitable for Warehouse 13 when objects begin to appear randomly around the town and GD, and it must be solved before there are deadly consequences.

Carter's camping trip with Kevin becomes a little scarier than ghost stories by the camp fire when a malfunction with the AI at Global Dynamics may turn some of them deadly. Elsewhere, Henry thinks about telling Grace the truth.

Love is in the air as Carter gets fed up with Grant's pursuit of Allison, Zoe conceals her love and Henry courts Grace. But all the emotions may have to be put on simmer when people in town start turning to stone.

Just as Carter and Allison seem to get everything right, people from their pasts appear to complicate things. Elsewhere, GD's new project perks the interest of Beverly Barlowe.

After the D.E.D. device disappears, Carter, Jo, Fargo and Allison find themselves in a déjà vu situation as their investigation puts Trevor Grant right at the top of the suspect list. The proverbial noose around his neck only tightens when they discover evidence that connects him to Beverly Barlowe, and her motive will put at risk everything they have struggled to achieve.

Carter can't get into the Christmas spirit especially with the town surrounded by a force-field. Fargo organizes the GD holiday party, and Allison is full of holiday cheer.

Zane pesters Jo for details she does not want to reveal. Carter problem solves at Andy and S.A.R.A.H.'s wedding. Elsewhere, Zane's actions make him and Fargo unexpectedly airborne.

Carter's duties expand to babysitting when Allison attends a medical conference, and Fargo finds his groove when a certain song is played. Meanwhile, a rocket scientist appears at Café Diem.

Lenses that predict security breaches are eagerly embraced by Jo, but not so much by Carter. Although he can't argue their importance after they both see the end of Eureka in one ghastly projected leap forward. Elsewhere, Fargo and Dr. Marten screen the hundreds of scientists who responded to Fargo's announcement of 20 open positions on the Astraeus Mission.

Carter deals with a bank robbery which may relate to the sudden gravity issues besetting the citizens of Eureka. Meanwhile, Fargo's rivalry with Isaac Parrish is boosted when he learns Holly and Parrish went on a date.

When Zoe comes home for a visit, Jo faces an angry woman who doesn't accept her fumbling explanations about Zane. This all fades to background noise, however, when they find everyone in Eureka unconscious and must find a way to work together so they can revive the town and beat Beverly before she gets hold of valuable data.

Global Dynamics deals with two threats — a visit from Senator Wen and robotic bugs that can consume everything; it's unclear which is the bigger one. Meanwhile, Allison refuses to acknowledge any deficit with which the implants may have left her.

Preparations for the Titan mission have the unintended consequence of turning the local Eureka environment into Titan's. Meanwhile, Eureka couples struggle to come to terms with each other and the DoD sends an investigator to evaluate Jack and Allison's relationship.

Attacks in town may scuttle the Astraeus mission in the same week the final 20 will be named. Carter and Allison appeal the auditor's recommendation, but the proposed fix, a memory reading gadget for the candidates' final interviews may give them more details about each other than desired.

When an explosion in the Astraeus lab accidentally sends Andy to Titan, the team must devise a plan to save him before it's too late.

The Astraeus participants make their farewells to their earthbound family and friends. Elsewhere, Carter and Jo investigate the person (or thing) which attacked the presidential convoy and if it is in any way related to the cosmic anomalies threatening Eureka.

Eureka is threatened by an intelligent drone with "issues" after an anti-missile test. Meanwhile, Eva Thorne, nicknamed "The Fixer", after dismantling and rebuilding several corporations, arrives in Eureka to evaluate Global Dynamics' expenditures.

Sheriff Carter and Allison investigate the disappearance of a scientist from a sealed biosphere. Meanwhile, "The Fixer" attempts to make Eureka's ventures more profitable.

The town's annual dog show gets into full swing—complete with exploding robotic canines. Meanwhile, Sheriff Carter experiences an isolated earthquake, Zoe contemplates quitting the accelerated physics program, and Allison starts fitting her wedding dress.

On Allison and Stark's wedding day, Sheriff Carter finds himself stuck in a time loop, causing him to experience the same lousy day over and over again. Meanwhile, Sheriff Carter's sister Lexi visits Eureka.

When an Egyptian tomb is opened at Global Dynamics, strange things start to happen, leading Fargo to believe it is the mummy's curse. The mummy, however, has disappeared, and Carter investigates.

A mysterious "superhero" who can walk through walls is causing a ruckus in Eureka. Meanwhile, Zoe and her friends become stranded with Zane Donovan in an abandoned subterranean facility.

The town's mayoral race is disrupted when Zoe's science partner inadvertently causes a second sun to appear over Eureka.

As Eva Thorne prepares to seal off the subterranean military complex, Zoe's life is endangered as her body begins to rapidly age.

Carter attends a job interview with the Department of Homeland Security. Deputy Lupo hands in her resignation on learning her new boss is a robot.

It is time for physical exams for the Sheriff's department and an upgrade for the town's security system, both Eureka-styled by Global Dynamics. Acting Sheriff Lupo seems almost loopy after the 48 hour extreme exam, and she volunteers to a DNA scan for the new security system, but then a malfunction occurs.

When objects begin moving on their own, Carter and newcomer Dr. Tess Fontana visit the "other side" to find the answer.

When the bowling team from Area 51 hits town, the long-standing rivalry-cum-war is reignited, and a prank goes horribly wrong. Now Carter not only has to mediate between Area 51 and the home team to prevent more destruction, but also deal with the consequences of the first prank: a blob with an insatiable appetite. Elsewhere, Duncan returns to plead his case to a resistant Lexi.

A wave of wholesale looting hits Eureka as the signal draws closer, and when the missing objects turn up in a field as part of five towers built by the town's sleep-building teenagers it becomes a race against time to find the cause. Meanwhile, Fargo breaks up with his car causing the AI to seek revenge after she's sold to Haberman.

Henry's 20-year-old project returns with more on board than it left with, and when a man is killed and another injured, Henry will have to face his past in order to save everyone's life. Back in town, Jo and Carter attempt to return the items from the towers to the owners with mixed results.

Carter investigates the deaths of scientists who drowned in less than liquid circumstances. Meanwhile, Allison's baby shower goes green.

Tess begins a time capsule project for the town on the same day as Global Dynamic's annual sonic cleaning. Unfortunately, Fargo's attempt to erase history leaves some with a form of amnesia, and two people trapped in Section 5 with very little time to remember how to stop the cleaning – and no way to stop Allison's labor.

The uneventful first day that Tess plans as the interim head of Global Dynamics is shattered by Taggart's reappearance and plunging temperatures caused by an ice core from the Arctic.

Tess' reign as head of Global Dynamics may be shorter than planned after she receives an offer from Australia. Elsewhere, the town deals with a magnetic disturbance and Carter must come to terms with Zoe leaving for college.

Reorienting himself to the timeline restored in "Once in a Lifetime", Sheriff Carter investigates a series of sudden deaths.

Carter and Stark are forced to team up when Global Dynamics is threatened by an expanding personal force field.

An isolated deep freeze trigger causes a chain reaction of sudden weather changes in Eureka.

After receiving a hit to the head, Carter finds that he is in a parallel Eureka where he discovers that its residents are mysteriously disappearing.

Space debris threatens Eureka after it accumulates into a large cloud and Carter investigates in an effort to avert potential disaster.

The denizens of Eureka are experiencing shared dreams. What is considered humorous at first soon takes a dire turn for the worse.

Douglas Fargo's grandfather, Pierre, is accidentally awakened from his cryogenic slumber. However, Pierre makes it clear that he was not willingly "frozen".

As an experiment that will recreate the first moments 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 hands of Jack Carter and an antisocial young ubergenius.

Strange happenings and spreading radiation at Global Dynamics lead to speculations that an abandoned research project concerning invisibility might have been revived. When Sheriff Carter accidentally becomes involved, the effects of invisibility threaten his life.

A series of strange events causes Eureka's residents to worry that a biblical plague may be upon them.

The women of Eureka become infatuated with Sheriff Carter, who they find irresistible.

Eureka faces an inexplicable quandary when metal objects—and people too—begin turning to gold.

Global Dynamics goes into lockdown to protect itself from the now airborne metal-eating bacteria. Stuck inside GD, Sheriff Carter and Stark must work together to save both the town and Kevin, Allison's son.

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. Carter learns about the secret purpose of the town while trying to re-establish a connection with his angry and bitter daughter, Zoe. 

Carter and the other citizens of Eureka attend the funeral of Susan and Walter Perkins. Much to their surprise, Susan makes a return to Eureka as a woman who is very much alive!

Jack Carter accidentally shoots Henry while suffering from short-term memory loss, and the visiting scientist whose wife is Henry's old flame may hold the only clues into that incident and the increasing memory losses occurring both in town and at Global Dynamics just as an important military contract comes due.

Spencer is apparently abducted by aliens and then returned to Earth the next day inside a crop circle. Also, the town is visited by Congressman Arnold Faraday, whose committee is responsible for Eureka's government funding.

After a lab accident, Global Dynamics researcher Carl Carlson is expelled from Eureka due to lack of results. Later, it is discovered that the accident has unlocked hidden abilities in Carl. Meanwhile, Jack does his best to avoid a physical.

After Fargo and Spencer accidentally activate a doomsday device, Carter must help Dr. Irwin Thatcher, an aging scientist, to shut down the machine.

Carter investigates an unusual car accident. Meanwhile, Stark is under stress to produce results on a project.

When the return of Eureka's star pupil causes problems all over town, Stark is forced to make a hard choice. Meanwhile, Carter attempts to track down Zoe who has run off with the former resident.

A nanotech experiment escapes from Global Dynamics. The project, which bridges the gap between computers and human brains, threatens to overrun Eureka when it begins duplicating Stark.

Sheriff Carter and Zoe are the only ones unaffected when Eureka's residents begin to behave strangely, so father and daughter team up to search for the cause.

S.A.R.A.H.—the artificial intelligence that runs Carter's house—takes him and a group of residents hostage in an intervention to keep Carter in Eureka. Meanwhile, S.A.R.A.H.'s root program B.R.A.D. activates and turns the situation deadly.

Following an experiment on the artifact, Eureka warps to 2010. However, temporal anomalies begin to cause problems for Eureka, which leads to a shocking revelation.