U.S. Marshal Jack Carter becomes stranded in a town populated with many of the world's geniuses.

A recently deceased woman shows up at Carter's office; a ghost-like figure appears in Allison's home.

When a world-famous scientist visits Eureka, Carter and Henry realise that they cannot account for blocks of time.

Carter investigates Spencer's alleged abduction; Eureka's funding may be in jeopardy.

A researcher taps into the power of a dangerous artefact, intensifying Stark's obsession.

After accidentally activating a doomsday device, Fargo, Spencer and Carter seek the help of an ageing scientist to shut it down.