Eureka is threatened by an intelligent drone with "issues" during an anti-missile test. Meanwhile, Eva Thorne 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.
Carter experiences an isolated earthquake at a farm, and the town's annual dog show gets into full swing. Meanwhile, Zoe contemplates quitting the accelerated physics program.
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.
Sheriff Carter investigates the disappearance of an Egyptian mummy from Global Dynamics.
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.