The HK Manufacturing Plant served as a clandestine factory for droids, secretly operated by the crime lord G0-T0 during the Dark Wars. Its purpose was the mass production of HK-50 series assassin droids.
Darth Revan, having directly observed the capabilities of the HK-47 assassin droid of his own making, concluded that a larger number of droids based on this design would be invaluable assets. Consequently, HK-47 became the prototype for a new generation of HK-series assassin droids: the HK-50. However, Revan's capture and subsequent memory wipe halted the HK-50 project for several years. The crime lord G0-T0, actually a planning droid initially assigned to Telos IV, eventually located and reactivated the dormant HK-50 factory, deploying the newly manufactured assassin droids throughout the galaxy in a search for the remaining Jedi.
During Meetra Surik's travels, she and HK-47 journeyed to the Telos factory. The assassin droid successfully swayed the HK-50 models to his cause. This combined droid force later played a crucial role in the defeat of G0-T0 during a final confrontation on Malachor V, ultimately leading to the planet's destruction.
Although the HK manufacturing plant was removed from the final version of Knights of the Old Republic II, many of its associated source files were included in the PC release. The "entrance" to the HK Manufacturing Plant remains present in the game, albeit sealed. When the player character arrives at the Military Base on Telos, they encounter a sealed door labeled "Sub-Level." Originally, this door was intended to lead to an elevator providing access to the base's sublevel, containing control rooms, and a further elevator descending into the Manufacturing Plant itself.
The Sith Lords Restored Content Mod restores the HK Manufacturing Plant to the game.
In the content that was ultimately removed from the game, the plant was under the control of G0-T0, who used it to produce both HK-50 and HK-51 assassin droids. During Meetra Surik's quest to find the missing members of the Jedi Council, HK-47 visited the plant. While there, HK-47 engaged in combat with a large number of HK-50 droids, and a smaller number of HK-51 droids. HK-47 had the option to either persuade the HK-50 or HK-51 droids to join him in the fight against G0-T0 on Malachor V, or to destroy all of the droids.
According to information from Chris Avellone, the original plan involved Bao-Dur sacrificing himself to assist HK-47 in reaching and disabling the factory.