Global Dynamics sonic cleaning coincides with a phenomenon in which the citizens of Eureka develop a communal form of Alzheimer’s disease. Meanwhile, Allison goes into labor.

Allison’s baby shower fetches her a load of eco-friendly gifts and the discovery of a drowned scientist in a location where drowning is impossible.

Jo displays atypical behavior after a DNA scan malfunctions, unfortunately it’s while she’s interim sheriff because Carter is undergoing a 48-hour DOD recertification test.

Trust issues are produced by a scientific find, along with sinister results. Zoe’s life is in jeopardy, and Eva Thorne knows what has caused the predicament.

It’s Allison and Stark’s wedding day and Carter finds himself reliving it over and over. Meanwhile, Carter’s sister, Lexi, visits the town.

Veronica uncovers information that her fellow outcast Mac was switched at birth with a more affluent student, causing Veronica to examine her own questions about whom her real father may…