Babylon 5: Thirdspace

An enormous artifact is discovered in hyperspace and towed to Babylon 5 for investigation. Interplanetary Expeditions assigns Dr. Elizabeth Trent to oversee the examination and take control of the project.

The artifact begins to influence the dreams of Babylon 5's inhabitants and gradually gains control over many, even during waking hours. A thrall network forms, led by Deuce, who demands a quicker excavation and grows increasingly hostile toward others.

Trent and a reluctant colleague decide to power up the device to accelerate the examination. They do so without informing Captain Sheridan, creating tension and a potential security breach aboard the station.

Sheridan and Delenn visit Lyta Alexander, who transmits a 'race memory' that provides crucial context about the artifact. The memory hints that the gate is tied to ancient Vorlon schemes and a danger from beyond human understanding.

Lyta explains that Vorlons built the gate a million years ago to reach the gods, but it connects to a dangerous parallel universe called Thirdspace. The Thirdspace aliens are telepathic, violent, and seek to annihilate other life. The revelation reframes the investigation's stakes.

Long ago, Thirdspace aliens telepathically converted a small Vorlon force to fight for them, leading to a stalemate. The non-thrall Vorlons shut down the gate, but the thrall Vorlons prevented its destruction by sending the artifact into hyperspace, where it was preserved for future awakening. This history explains why the artifact could reappear and threaten Babylon 5 again.

Lyta telepathically informs Captain Sheridan how to deactivate the gate, outlining a countermeasure embedded in the Vorlon telepathic code. The team prepares to use this knowledge to avert catastrophe before the device is reactivated.

The device is reactivated and Thirdspace aliens stream out from the portal in small fighters, beginning a devastating assault on Babylon 5. The invaders’ ships are highly advanced and use deflector shields, making them extremely difficult to destroy. The telepathic influence still at work among the thralls appears to disrupt the station's defenses.

Babylon 5's defenses are compromised as thralls fight against the station's personnel while the Thirdspace fleet presses the attack. The battle tests the crew's resolve while the odds tilt against Babylon 5 due to the new technology and mind control. The team races to implement the deactivation plan before the station falls.

Sheridan deploys a thermonuclear device and destroys the artifact just as the first wave of Thirdspace heavy warships emerges. The destruction halts the mind control and the station's defenses begin to recover as the alien threat wanes. With the artifact gone, the telepathic influence ends and life on Babylon 5 returns to normal.

Trent, shaken by the artifact's effects on personnel, turns over her final report to her superiors and begins an indefinite hiatus from field work. She expresses lingering doubts about the nature of the artifact and the implications of the findings.

Sheridan and the survivors conceal the artifact's true nature from those who ask questions, convincing themselves that the incident is unlikely to recur. In private, Lyta broods with the knowledge that the Vorlons have made many mistakes, hinting at a broader caution about their plans.