In 45 ABY, the Columi brothers, Craitheus and Marvid Qreph had discovered an unidentified monolith at the heart of the Chiloon Rift. They built a fortess, Base Prime on the monolith above a Space–time-warping gate which granted access to the monolith. Upon study of the monolith, they discovered that it had the ability to grant those that entered the powers of the Force. To keep anyone else from interfering in their plans for the monolith, they organized a hostile takeover of the Chiloon Rift through dirty business dealings. These dealings brought them into conflict with the New Jedi Order, and as the conflict escalated, the Qrephs captured Han Solo, a friend of the Jedi. Solo was brought to Base Prime and tortured as the Qrephs prepared to enter the monolith. However, before they could enter, the Jedi discovered the monolith and prepared an assault to rescue Solo and stop the Qrephs.
The Qrephs were protecting their base with the biotically created species, the Nargons. To lead their forces, they had hired Mandalorian warriors led by Mirta Gev. However, when the Jedi arrived to attack the base, the Qrephs' Force-sensitive agent, Vestara Khai, under the alias of Savannah Raine, coerced the brothers into letting her lead the defense. However, Vestara had not predicted the speed of the Jedi attack or their use of YVH-Series battle droids. The Jedi easily breached the base, and Raine was forced to call a retreat. She evacuated the Qrephs through their residence to escape the advancing Jedi, but the maneuver resulted in the severe wounding of Craitheus. Marvid, fed up with Vestara's meddling in their affairs, betrayed his agent, shooting her in the legs and made his way to the gate to access the monolith.
Mirta Gev, realizing the battle was lost, agreed to help Vestara escape Base Prime in her ship, the Sith Meditation Sphere, Ship, leaving the Qreph brothers to fend off the Jedi on their own. She ordered her Mandalorians to abandon the Nargons and escape. As the Jedi took over the base, Vestara and Gev used Ship to escape. Ben Skywalker, who was leading the Jedi force, searched the base for Vestara and Gev, but was unable to find them. The battle won, Base Prime was destroyed by the Jedi and the monolith cordoned off from further interactions.
Leia Organa Solo and Luke Skywalker followed the Qrephs into the monolith and them, but they were unable to locate the Qrephs' agents.