On tonight's season finale of Fringe - "There's More Than One of Everything" - someone "with close ties" to the Fringe Division is attacked. Meanwhile, ZFT bioterrorist David Robert Jones returns and Walter mysteriously disappears. The season finale features Leonard Nimoy of Spock of Star Trek fame as Dr. William Bell. Fringe co-creator Roberto Orci previously revealed that Nimoy's character will return this fall for an extended arc, in at least two episodes, and is going to be "the beginning of the answers to even bigger questions." In an interview, Nimoy described the final scene of the episode, which he shares Anna Torv, who plays Olivia.
"It's very brief, but I think interesting, entertaining and there's enough given in the scene to whet your appetite, that you'll want to see more of this relationship and what it's all about. You'll want to know what it is he has in mind with Olivia, what he wants or needs her for, why he wants to see her, what their past history is about and where they're going together."
On the last episode of Fringe, the team investigated the case of a woman who spontaneously combusted in the middle of a busy New York street, to discover eventually that the victim was the subject of a ZFT experiment to cultivate pyrokinesis. During the course of the investigation, Olivia started experiencing visions while awake, which Walter suggested can be some kind of parallel reality. Olivia and Peter visited an agoraphobic website designer who may know William Bell. Thanks to Olivia's visions, they were able to track down the victim's twin sister, who was also kidnapped for more experimentation. She and Olivia ended up locked in a room, whose unstable pyrokinetic abilities endangered both their lives. Later on, the Observer showed up and took Walter away, saying "it is time to go." Nina Sharp, meanwhile, visited Broles to discuss the Observer, and was to be shot in her hotel by two masked gunmen.