When a prototype sets everyone into bad temper mode, the issue escalates and gets worse beyond the control of what Jack can handle. As Jack and Allison and Tess are the only sane people at Global Dynamics they have to devise a plan that will make everything calm and happy again. Meanwhile, Henry is helping Dr. Grant re-build the bridge that got them back to the new world except everything they touch disappears.

The Astraeus candidates go through their final interviews while Carter and Allison appeal their relationship audit.

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! Eureka

In the season finale - It's chaos in Eureka when an energy beam rips through main street but the Astraeus launch must go on...with or without Eureka intact.

The Astraeus crew returns to Eureka four years later and must adapt to a myriad of changes, including a more oppressive version of Deputy Andy.

When Allison's genius older brother comes to meet her new husband, Carter feels the pressure of not being smart enough to measure up.

The people of Eureka are being kidnapped and replaced by body-doubles one by one unless Allison, Fargo and Zane can figure out how to avoid capture and save their town.

Wormholes randomly materialize around Eureka as the Department of Defense is set to shut the town.