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 swingcomplete 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 Jack 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 three 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.

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

It's a busy day for Global Dynamics and Eureka as Allison's labor begins during a sonic cleaning of the company, and the townspeople exhibit Alzheimer's disease at the same time.

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, the town deals with a magnetic disturbance and Jack must come to terms with Zoe leaving for college.