During the waning conflict between the Republic and Empire in 26 ATC (Onslaught in SWTOR), Czerka Corporation now under the name Czerka Interstellar lost contact with their private Research Facility on Dxun. With no other option, they made contact with heroes of the Republic and Empire discretely on Onderon to ask for help.

The Czerka Facility on Dxun, known as CI-004 Research Facility was a secretive facility owned by a privatised branch of Czerka Interstellar that had escaped a hostile nationalisation takeover of Czerka Corporation by the Galactic Republic after the events of CZ-198. The Dxun Research Facility served as a base to enact Cybernetic experimentation, Biological augmentation and Evolutionary Warfare Research without oversight from the major branch of Czerka themselves.

The Facility itself bare a strong inspiration from the design and security used by Jurassic Park in the movie franchise with a similar plot line throughout the Operation.

Mex Briggam, Chief Engineer of Czerka Corporation contacted the group of Heroes where he and Nara Sefalla made contact on Onderon to send the group as a “Security Force” to contain and potentially resolve an ‘Incident’ that had occured at the Dxun Research Facility.
The team landed outside the facility and made way through the exterior jungles with help from Trey Adelair who would oversee the ground team via radio communication. The team was able to find their way insie after disabling the outer-walls electric security fences which enabled experimented creatures to break free and wreak havoc throughout the base.

Once inside, the team was quickly swarmed by hordes of Trandoshan Hunters that had overrun the interior of the Research Facility, thinking on their feet with the help of Adelair, the group was able to use power cores to activate ARIA, an AI System capable of controlling the Research Center in order to take the building back from the Trandoshans.

This would come to a penultimate end as four of the Trandoshans: Hissyphus, Greus, Titax and Kronissus had broken into the Research Facilities Evolutionary Warfare Lab, where they were mutated into hulking monstrosities now augmented with super powers and capable of self-regeneration.
The group of Heroes was able to defeat the four Mutant Trandoshans by tricking them into self-regenerating within a set of railway tracks. Here they were able to call a train and run the Trandoshans over, exploding each one in the process.

However the Dxun ‘Incident’ was far from over, as Czerka revealed that deeper parts of the Facility were no longer secure and still required help. Begrudgingly the team travelled deeper through the facility to check one final room and on their way, fell into a Bio-Dome containing hordes of stampeding creatures and a female Trandoshan Huntmaster.
The group made use of light flares to defend themselves from the light sensitive creatures until the Huntmaster herself was caught offguard enough to be consumed by a giant crab named “Shelleigh” that emerged from a nearby lake within the Bio-Dome.

With no other obstacles in their way, the team entered the heart of the Research Facility, a giant suspended containment Laboratory that housed the Apex Vanguard.
The Apex Vanguard was a hulking, cybernetically enhanced Rancor-like creature that had been augmented with light-sensitive regeneration abilities, backpack guided missiles, acidic spit and increased senses and aggression in the dark. It was here that the team engaged in combat with the beast, using research machines within the laboratory to alternate the power by overloading batteries as well as concocting makeshift stims to enhance themselves against the creature.

As the Apex Vanguard fell, the ‘Incident’ on Dxun was no more. Czerka voiced their displeasure in the downfall of the Apex Vanguard as they had wished to produce more for profit, but agreed that what had happened had to happen. Czerka was also able to salvage the ARIA AI core from the facility and congratulated the Heroes for a job well done back on Onderon.

Sources:

Dxun Story Quest – Onderon (Onslaught)
Operation: “The Troubling Nature of Progress”
Dxun Cipher/Codebreaker Achievement
Voice lines present from Trey Adelair given throughout the Operation.
ARIA voice lines present throughout the Operation.