An attack was launched against the Epsilon Nine Communications Research space station in 4 ABY by Lumiya in conjunction with forces from the Galactic Empire. Director Ysanne Isard of Imperial Intelligence contracted Lumiya to inspect the progress of several highly classified Imperial research facilities within the Cron Drift, offering military support in return. The New Republic had recently taken control of one of these facilities, Epsilon Nine, aiming to liberate the scientists from Imperial control. As Lumiya's fleet entered the Auril sector, New Republic forces engaged them. Lumiya unleashed her newly strengthened armada, swiftly overwhelming the insufficient New Republic defenses. She personally boarded the research station, intending to shatter the scientists' faith in the Republic's protection and reassert Imperial authority. Lumiya's presence instilled fear in the Imperial defectors, and the threat of lethal force successfully coerced Epsilon Nine's staff into reaffirming their allegiance to the Empire. Assured of their compliance, Lumiya and her fleet departed Epsilon Nine, promising to return in a few months to ensure continued cooperation.
Following their defeat at the Battle of Endor by the Rebel Alliance, which later became the New Republic, the Galactic Empire was significantly weakened, but many facilities remained operational, including several secret research installations hidden within the Cron Drift. Aware that the New Republic sought to dismantle the Empire's oppressive rule throughout the galaxy, researchers at one facility, the asteroid-based Epsilon Nine, attempted to break their Imperial ties by offering their services to the Republic. However, Imperial Intelligence agents immediately discovered their act of treason.
Director Ysanne Isard was approached by Lumiya, who requested resources after most of her own fleet was destroyed during the Nagai–Tof War. Isard agreed to provide Imperial naval support to bolster Lumiya's depleted fleet, but with conditions. In return, Lumiya would travel to the Cron Drift on behalf of the Empire to assess the progress of the Imperial facilities and, if necessary, force them back into Imperial service.
The Nebulon-B escort frigate Revenant served as Lumiya's command ship as her fleet journeyed to the Cron Drift. After detecting a weak radiation pulse from the Communications Research Station, she instructed Captain Valek of the Revenant to slow the fleet's speed and avoid contacting Epsilon Nine. Moreover, the station's comlink system was found to be transmitting on New Republic frequencies. The Revenant's scanners then picked up nine T-65 X-wing starfighters rapidly approaching the fleet. Lumiya ordered the deployment of TIE interceptor squadron Alpha and TIE/sa bomber squadron Theta, while also directing the Revenant to provide turbolaser fire. Simultaneously, the Revenant's two escort CR90 corvettes, Wolf-Pack and Borealis, disabled Epsilon Nine's defensive laser batteries. The X-wings were quickly destroyed by the combined attacks of the Revenant and the TIE interceptors. Epsilon Nine's attempts to attack the Revenant were futile, as Wolf-Pack and Borealis eliminated the space station's ground defenses and the New Republic troops operating them. Theta Squadron also breached Epsilon Nine's landing platform with a barrage of proton torpedoes.
Wolf-Pack launched two assault shuttles carrying squads of elite red-armored stormtroopers specially provided for Lumiya's fleet by Isard, while Borealis deployed a pair of HAVw A5 Juggernauts onto the asteroid's surface to directly assault the station's central complex. The Juggernauts decimated the opposition, creating a clear path for the stormtroopers to quickly enter the station. Although outnumbered by Epsilon Nine's security forces, the stormtroopers prevailed. With the station secured, Lumiya arrived on the asteroid in a Lambda-class T-4a shuttle and prepared to take control of the situation.
The complete annihilation of the New Republic military force, with only minor injuries among the Imperials, resulted in a successful mission at Epsilon Nine. Lumiya received this report upon entering the command center, ready to interrogate the scientists. After one particularly defiant individual mocked her for being female, the Dark Lady used the Force to crush his throat. She denounced the remaining scientists as traitors but offered to pardon their insubordination, shattering their morale by destroying a sigil bearing the emblem of the New Republic with her lightwhip. To prevent future attempts at rebellion, Lumiya ordered her garrison to occupy the station in her absence, ensuring their continued loyalty to the Empire. Before departing with the rest of her fleet, Lumiya promised to return in eight weeks, expecting the completion of the spy satellites that Epsilon Nine was originally tasked with developing.
Despite being driven from the Cron Drift and forced back into Imperial service, the scientists of Epsilon Nine maintained hope of eventual rescue by New Republic reinforcements. The station continued to emit the weak radiation pulse initially detected and ignored by the Revenant, believing that it would reach the Cron Drift's satellite grid, where New Republic operatives would recognize it as a distress signal and send help.
The assault on Epsilon Nine was first featured in Michael Mikaelian's short story Lumiya: Dark Star of the Empire, published in 1995 by Topps for Star Wars Galaxy Magazine 3. An explanation for Lumiya's acquisition of Imperial warships and Royal Guards (red-armored stormtroopers) from Ysanne Isard is provided in Abel G. Peña's 2006 online supplement for Star Wars Insider 88, titled Evil Never Dies: The Sith Dynasties. Further details about Lumiya and Isard's relationship are discussed in Lumiya's entry in an article by Juan Schwartz, Pablo Hidalgo, and Abel G. Peña for Star Wars Gamer 5, titled The Emperor's Pawns.
In Dark Star of the Empire, Lumiya mentions the New Republic's attempts to seize Imperial technology being developed in the Elrood sector as her fleet approaches the Cron Drift. However, other canon sources place the Drift in the Auril sector of the Outer Rim Territories. It remains unclear whether Lumiya was referring to other Imperial installations or if the author made an error, as Dark Star of the Empire does not mention the Elrood sector again.
The galactic map "The New Republic Advances (4-6 ABY)" in The Essential Atlas depicts the assault on Epsilon Nine as a circle centered on the nearby Ossus system.