- "Codename: Gemini. Continue our investigation."
- ―SCORPIO, to Thea
The GEMINI units were sentient droids that operated the Eternal Fleet. The Eternal Throne allowed the ruler of the Eternal Empire to communicate with and command the GEMINI units. Their existence was relatively unknown, even within the Eternal Empire. SCORPIO was investigating them during her time on Zakuul, and Arcann occasionally received reports from the GEMINIs via holo rather than text-based communication.
The GEMINIs were in essence copies of two advanced droids: SCORPIO and GEMINI Prime. The latter of these needed to act as a template, as fabricating GEMINI droids wasn't easy; SCORPIO stated that this was because her technology wasn't easy to duplicate. The GEMINI droids acted as captains aboard each warship in the Eternal Fleet and were slaved to the Eternal Throne. However, the GEMINI frequency had a few vulnerabilties:
- If anyone were to reach the hyperwave relay station beneath the Spire, destroying it would force the GEMINI units back into dormancy or controlling it will enable them to send fake orders.
- Plugging GEMINI Prime into the captain's interface of an Eternal Fleet warship would enable the user to overwrite the existing protocols and take control.
Three thousand years before the Galactic War, an unknown race constructed GEMINI Prime, based off the technology of SCORPIO, and through the Prime, they constructed an unknown number of copies to act as captains of the Eternal Fleet. The Eternal Fleet conquered nearly all of Wild Space, before the Gravestone deactivated the fleet and forced it into dormancy.
The fleet would be reactivated centuries later by Valkorion, the Immortal Emperor of the Eternal Empire, who slaved the GEMINIs to the Eternal Throne so he could command the fleet. Control of the GEMINI units later fell to his son Arcann, after he betrayed his father, and unleashed the might of the Eternal Fleet upon the entire galaxy.
As the years passed, the Alliance eventually recruited SCORPIO, or the Lady of Sorrows as she was known as then. During SCORPIO's time opposing the Eternal Throne, she had begun to research the GEMINI units, leading to various discoveries such as the Hyperwave Relay Station, or GEMINI Prime. Although the mission to secure or destroy the Hyperwave Relay Station resulted in failure, the Alliance did succeed in capturing GEMINI Prime on Darvannis.
Following the capture of GEMINI Prime, SCORPIO devised a plan for the Alliance to gain total control of the GEMINI units. After finding a lone warship, SCORPIO and the Outlander launched their assault under the pretense of planning to plug GEMINI Prime into the captain's chair - something that would have given the Alliance control of the Fleet.
Unbeknownst to the Outlander and the Alliance, SCORPIO had no intentions on giving the Eternal Fleet to the Alliance. After faking her death, she granted the GEMINI captain free will of its own. SCORPIO waited until Arcann's fleet had left Zakuul in an attempt to confront the Outlander before seizing the Eternal Throne for herself, and used it to seize the majority of the Eternal Fleet, save for Arcann's detachment (the Eternal Flagship being able to control nearby warships directly).
By the time of Arcann's defeat at the Battle of Odessen, SCORPIO had managed to grant continued free will to the remaining GEMINI units, calling them her children. And when Vaylin came to seize the Eternal Throne for herself, SCORPIO stepped aside with the promise that she and her children would continue to aid the newly appointed Empress Vaylin in destroying their enemies.
Later, one of the GEMINI units was spotted on Hoth by a contact of Hylo Visz. As evidence of their newly granted freedom, the contact reported that the Eternal Fleet's warship landed on Hoth's frozen surface, allowing the GEMINI unit to step out and take in the snowy landscape. After a few minutes of simply watching, the GEMINI unit returned to the warship and left without a word.
Later on, during the invasion of Voss, most of the GEMINI captains chose to flee when the Sith Empire aided the Alliance in defense of the planet. This earned the anger of Vaylin, who threatened to dismantle all GEMINI units, though SCORPIO reminded her that she gave her children free will, allowing them to make a choice the empress disagreed with.
SCORPIO and Vaylin later captured the Gravestone, having sacrificed two ships to mask their ruse of attacking a freighter. Subsequently, the Eternal Fleet battled against the Alliance fleet again, which had responded to Koth Vortena's distress call.
When SCORPIO had successfully taken control of the Gravestone and discovered the location of Iokath, the planet where SCORPIO, the GEMINIs, their fleet and the Gravestone were created, sent them to the place of their creation. Upon entering the mega-structure, Iokath's caretaker, ARIES, utilized Iokath's planetary weapon that incapacitated both organics and droids temporarily. The Outlander's crew, Vaylin and SCORPIO were separated to be tested on whether any of them were worthy of inheriting Iokath, while the Eternal Fleet and the Gravestone were docked at a spire. Eternal Fleet personnel, including the GEMINIs, were removed from their ships.
Two GEMINI units met up with some of Vaylin's forces before the empress herself rejoined them. One GEMINI protested Vaylin's decision to retake the Eternal Fleet, recalling her sisters who died on Voss and expressed fear, at which the empress tossed the insubordinate droid off a precipice. This cowed the remaining GEMINI droid into compliance. Once half the Fleet was freed, the remaining half were towed with tractor beams.
Vaylin brought aboard one of her ships the remains of a Purifier droid and ordered the GEMINI captain to plug into its memory core for information on ARIES. Once the location of ARIES' base and that the caretaker droid were preparing Iokath's weapon to neutralize all his enemies were confirmed, the GEMINI captain reluctantly complied with Vaylin's order to send a detachment of ships to destroy it. The Purifier then noted that SCORPIO's free will protocol impeded GEMINI's judgment and offered to reset her to default protocols. When GEMINI refused to remain on Iokath, knowing ARIES' weapon would damage her, Vaylin had the Purifier wipe away her free will, forcing GEMINI to obey without question. After escaping Iokath and returning to Zakuul, Vaylin had the Purifier reset all the GEMINI droids to default protocol (via the Eternal Throne), and tested it by having one Eternal Fleet ship destroy another.
After the Outlander killed Vaylin during the second battle of Odessen, the Eternal Fleet retreated. Without a master and with their free will again removed, the Fleet reverted to its most primal instinct - extermination - and began rampaging across known space, bombarding worlds such as Coruscant, Dromund Kaas and Zakuul. The Outlander put a stop to their rampage by seizing the Eternal Throne.