This week Eureka uncovers a hidden spy conspiracy that has the town wondering who among them are traitors. Before things go bad, however, the day starts out positive with Jack and Allison finally off to enjoy their honeymoon.
Allison's hoping for a tropical paradise. However, that's not what Jack has in mind. Instead, he takes her to the broken down cabin of his predecessor. He wants them to work together to turn into their dream cottage.
Allison's not convinced until Jack pulls out a tool belt with her name on it. Then he pulls wedding bands out too, softening her further. That's until she gets a look inside the cabin. Then she suggests letting Global Dynamics engineers design them a brand new one.
Jack balks at that idea, saying he wants to put down roots with her. Only then he falls through rotted floor boards, exposing a hidden safe. The couple calls Andy to open it. When they do, they find case files inside. Jack gives the files to Andy to check so he can get back to his honeymoon.
Sadly, that's short-lived. Rain showers uncover a leaky roof. Still, the couple makes do until the roof caves in on them. Allison still tries to keep it together for Jack, until her shower turns into a mad bath instead. She's had enough.
That's when Jack sees he has 40 messages from towns folk inquiring what he's doing about the spies. The couple heads back to town to see what's going on.
It turns out that the files Jack gave Andy show that a spy conspiracy's taking place. While Jo thinks the files were talking about Beverly Barlow, Andy points out that one spy doesn't make a conspiracy.
When they find a strange disk in the files, they take it to Henry. He says it's an old-fashioned optical data storage device. He promises to try to find a way to reach its information.
In the meantime, his wife Grace is working with Zane and Fargo to put Holly's consciousness into a fabricated body. The process works and Holly awakens. However, she soon starts acting paranoid, insisting they're still inside the virtual world.
Zane runs diagnostics and discovers that her mind is degrading, causing her detachment from reality. No one understands just how bad it is until she cowers from Jack, remembering it was his virtual self that killed her. She pulls his gun on him, planning to shoot until Fargo steps between her and the sheriff. Then he takes the gun away from her.
Zane decides they must reprint her consciousness into the body a second time. But will it work?
As two couples struggle to survive, a third could get blown apart. Henry rigs up a machine to read the optical disk as planned, but the machine burns up instead. Someone tampered with it. He and Jo set a trap to catch the culprit. Unfortunately, it turns out that it's Grace.
At first, she offers no explanation, leaving Henry and Allison confused, given that Beverly Barlow's machinations nearly cost her a family and Jack. She doesn't believe Grace's claims she knew nothing about what Beverly had in mind.
Eventually, even Henry wants to know why Grace turned traitor. She tells him there was a time when she worried about the things GD was doing. However, she says she no longer believes them evil. She tells Henry she didn't know about Senator Wen or Beverly's plans for the Astraeus crew.
He asks her why she tried to destroy the disk. Who was she trying to protect? Hesitantly, she admits it's the Henry who existed before the timeline change.
Back in the lab, Zane completes Holly's reprint. She comes out of it her old self at last. All is right, at least in Fargo's world.
As Jack works on the cabin's roof, he's surprised to see his wife drive up. She tells him after witnessing what other Eureka couples were willing to endure for one another, she feels she can do the same. The honeymoon is back on.