Babylon 5: Thirdspace

Plot

An enormous artifact discovered in hyperspace is towed to Babylon 5 for investigation. The xenoarchaeology corporation Interplanetary Expeditions sends Dr. Elizabeth Trent to oversee its examination. The artifact begins influencing the dreams of many station inhabitants, eventually controlling them while awake. These thralls, led by Deuce, demand faster excavation and grow violent.

Dr. Trent theorizes the artifact is a Jumpgate leading to a third space. With her colleague's reluctant support, she orders activation without notifying Captain Sheridan. Sheridan and Delenn consult Lyta Alexander, who transmits a race memory: the Vorlons built the gate a million years ago to contact what they considered gods. They discovered Thirdspace, a parallel universe inhabited by an ancient, powerful telepathic species bent on exterminating all other life.

The aliens converted Vorlons to fight for them; the battle ended in stalemate, with non-thrall Vorlons shutting the gate and thralls sending it into hyperspace. Lyta telepathically tells Sheridan how to deactivate it.

Story arc significance and continuity

The film is a stand-alone episode set after the Shadow War and before war with Earth was declared. Continuity details, such as the presence of Dr. Franklin and Delenn and changes to Zack Allan's uniform, place events during or just before the episode Atonement, though continuity problems can be resolved. A scene shows Zack Allan revealing his feelings to Lyta Alexander, unaware she is telepathically dominated and does not hear him, shedding light on their friendship and his jealousy of her relationship with Byron in Season 5. In The Fall of Centauri Prime, Delenn obliquely references the film by wondering about a million-year-old jumpgate left by the First Ones. The artifact was designed by Wayne Barlowe; the novelization describes it forming into a jumpgate larger than the station, while in the film it rearranged and decreased in size.