An accident leads a U.S. Marshal and a teenage girl (who later is revealed to be his daughter) to a peculiar town populated by scientists and their families where 10-year-old boys are in 11th grade, the local diner doesn't believe in menus, and E=MC² was just the beginning. Just as the Marshal starts to get settled into the swing of things, a local scientist develops a bomb that seems to appear anywhere and eats all the matter around it.

The citizens of Eureka attend the funeral of Susan Perkins, only to find out that she is in fact alive. Meanwhile the Sheriff moves into an underground bunker that is actually a 'smart house' controlled by a computer dubbed 'S.A.R.A.H., and begins to investigate a 'ghost' that has been appearing in town.