When the microbots assembling the Titan space craft finish their task they opt to take on a new project and proceed to devour Eureka in the process. In isolation for a mission evaluation the Titan team can't tell if the microbot catastrophe is real or just part of the test.
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.
Sheriff Carter and Allison Blake are secretly planning the perfect holiday surprise for their kids. But a mysterious kaleidoscopic wave of color crashes over Eureka, leaving the entire town and its inhabitants animated.