The Second Core is an ancient Progenitor-built hyperspace drive core. Much like its "siblings", the Second Core was a powerful artifact of a bygone age, one of the legendary "Three Cores".
According to the Bentusi, in ancient times before recorded history, in the First Time of the Progenitors, the Three Cores were forged by the great Progenitor Sajuuk in the Foundry of the Progenitor Mothership, unlocking the mysteries of Hyperspace for his people. As the eons passed, the Progenitor civilization collapsed, and the Trinity was separated.
A long time later, the Second Core was found by the Hiigarans, deep within the heart of the shattered wreck of a gigantic starship in the Great Wastelands, circa the 7th millennium GSY. It was known that it was as powerful and as capable as the First Core, owned by the Bentusi.
After its containment units were extensively modified, it was mounted on the newly-built Hiigaran flagship - the Sajuuk's Wrath, to carry out their vengeance upon the Taiidan Empire, whom they had a territorial dispute with. After gathering their entire fleet, the Hiigarans attacked the Taiidan forces from deep within their own borders, eventually reaching their homeworld, Taiidan, and bombarded it for a full day, destroying all of its military installations and the Imperial Palace itself. The Hiigaran incursion on the Taiidan Empire lasted only 67 hours.
A few days after Taiidan's bombing, the outraged and usually slow-acting Galactic Council demanded that the Hiigarans immediately turn the core over to them for safekeeping, abandon the territories disputed with the Taiidan, and any Hiigaran Navy military vessel that was within the 30 light-year exclusion zone that separated both empires. The Hiigarans accepted, on the condition that the Great Harborship of Bentus would be its safekeeper. One day later, when the Bentusi jumped in the Hiigara System to take the core, the entire Hiigaran Navy attacked the Bentusi. After a short and horrific battle in which both fleets were devastated, only Sajuuk's Wrath and Bentus were left. When the Sajuuk's Wrath's sublight engines were destroyed, its commander made his ship jump on a collision course towards the Angel Moon, destroying it.
In the month before their Exile, the Hiigarans retrieved the Second Core from their moon, and it was safely hidden inside the Khar-Toba, which eventually arrived in Kharak. Having crashed in the Great Banded Desert of the world's equator, the Hiigarans built a city around the crashed ship, which lasted for many years. Eventually the Second Core's fusion power plant stopped working, forcing Khar-Toba to be abandoned, its people moving to Kharak's northern polar regions. Even without its power plant, the Second Core still generated intense emissions, producing an energy signature that rivaled Kharak's star.
At some point, at least 1000 years before its rediscovery by the Kushan, the Second Core malfunctioned and formed a massive interference bubble that extended beyond the Kharak system, causing severe malfunctions on the hyperspace drives of ships passing through and near it. These issues ranged from pulling the vessels out of Hyperspace and crashing them on the planet's surface to redirecting an entire fleet of frigates in hyperspace and materializing them under the surface of Kharak. A notable vessel destroyed in this manner was a Taiidan carrier that was deploying an orbital Ion Cannon in Kharak's orbit, presumably for the purpose of preventing the exiles from returning to space. The Core remained forgotten until 1106 KDS, when Leykab Jaraci accidentally found a huge metal object while analyzing the data tape of a malfunctioning Viin Cal radar satellite. Before it was confirmed to be the Khar-Toba, it was known both as the Jaraci Object and as the Primary Anomaly.
The Kushan sent two expeditions to find the metal object. The first, Operation Skaal Brii, was a failure due to a lack of preparation and a massive sandstorm that trapped the Ifriit-Naabal, the land vehicle sent to investigate the Object. The second expedition, Operation Khadiim, successfully found the ship/city in 1110 KDS. When the Kapisi returned to the Coalition of Northern Kiithid's territory, the Second Core was sent to Tiir in 1112 KDS and after extensive repairs and modifications, including the replacement of the containment units to meet the lower power output of Post-Exile technology, it was mounted onboard the Kushan Mothership in 1216 KDS.
After the surviving Kushan returned to Hiigara, the reformed Daiamid argued over what was to be done with the Second Core. Kiith Naabal and the Kiith Manaan wanted to continue using the Core, while Kiith Soban and Kiith Somtaaw wanted to stop using it. In the end, the decision came to the hands of Karan S'jet-Sa, the Kiith-Sa of Kiith S'Jet, and the Sa of Sas: The Core, regardless of its power, was best left as a monument to the trials and triumphs of the Hiigaran people, rather than press it back into service.
The Second Core was moved to a Museum in Assam Kiith'Sid, the new capital of Hiigara, according to the S'jet-Sa's wishes. Over a century later, when she realized that a war with the Vaygr was unavoidable, Karan asked for the Core's reactivation, on the condition that she would command her people once more. The Second Core was moved to Tanis Station and later used onboard the Pride of Hiigara. When the Hiigaran Navy retrieved the Progenitor Dreadnaught, and Bentus self-destructed itself to save them from 4 Keepers, the Hiigarans took the First Core as well. After reaching the center of the galaxy, with the help of the Balcora Gate, and destroying Makaan's flagship, the Third Core was taken too. Karan then combined the Trinity with an ancient Progenitor battleship named after their creator, Sajuuk, becoming the Sajuuk-Khar, the Chosen One, and the Custodian of The Three.
After returning to Hiigara and using the Sajuuk to save the planet from the Vaygr's Planet Killers, the restoration of peace to the galaxy, and the discovery of the Eye of Aarran, Karan used the combined power of the Trinity to reactivate it, reviving the long-forgotten Great Network of Hyperspace Gates and starting the Age of S'jet.