During the Galactic Civil War, a violent offensive was launched by prisoners from the Galactic Empire's Accresker Penal Legion against a rebel EF76 Nebulon-B escort frigate.
Subsequent to the infiltration and destruction of Hivebase-1 circa 1 ABY, Captain-Inspector Magna Tolvan initiated an attack directed at the Son-tuul Pride. The confrontation proved to be brief, with only the leaders, 0-0-0 and BT-1, successfully escaping. The remaining members of the Son-tuul Pride were taken into custody. Among those captured was the unscrupulous archaeologist Chelli Aphra, who had been the mastermind behind the infiltration of Hivebase-1. Tolvan incarcerated her within Accresker Jail, compelling her to serve within the ranks of the Accresker Penal Legion.
An Alliance EF76 Nebulon-B escort frigate found itself in a dire situation, crippled after an engagement with a pair of Imperial-class Star Destroyers. Subsequently, the Accresker Penal Legion received orders to board the stricken vessel. Transported via hyperspace on the jail, which was being towed by Accresker prison-tug vessels, they executed a controlled collision to secure themselves to the frigate, enabling the deployment of the prisoners.
The prisoners made their way through the corridors, eliminating numerous rebel troopers with their weapons. They were under the command of their hubdroids, which dictated that they remain within a ten-meter radius during combat to prevent the detonation of their implanted micro-explosives. Regrettably, one prisoner, identified as Convict 2317, suffered a foot injury and lagged behind as his squad proceeded forward. Consequently, the hubdroid triggered the prisoner's micro-implant, resulting in its violent explosion before they could rejoin the group.
As 2317 was incinerated, the hubdroid continued to urge its squad to advance, but Chelli Aphra cleverly deceived it into believing that rebel commandos were positioned ahead. She then sought cover behind her fellow prisoners as they, along with the hubdroid, unleashed a barrage of fire. The hubdroid experienced a malfunction and detonated, eliminating the entire squad with the exception of Aphra and a prisoner known as Lopset Yas. With the hubdroid destroyed, the micro-implants within Aphra and Yas were primed for detonation. However, another squad arrived just in time, consisting solely of its hubdroid, the droideka Dek-Nil, as the remaining members had met their demise through a series of suspicious incidents. Yas pleaded with him to join his squad, and Dek-Nil spared him and Aphra from their impending doom.
Aphra recognized Dek, having previously collaborated with him on Hivebase-1. She introduced Yas to Dek-Nil and vice versa before embarking on a search for an escape route. When Yas inquired about Aphra's acquaintance with Dek-Nil, she revealed that she had reprogrammed him and that his restraining bolt was connected to a non-functional control circuit, rendering it incapable of controlling him.
Subsequently, the trio encountered a protocol droid and an astromech concealed within an escape pod. Aphra and Yas swiftly eliminated them, and Aphra questioned Yas's worthiness as an escape companion. At that precise moment, Dek-Nil's restraining bolt began to emit a glow, and it initiated the process of assuming control of his actual control circuit, compelling him to identify and destroy the escape pod. Aphra and Yas then turned their attention to a Force spirit, which had disrupted their escape attempt. However, before they could contemplate its nature, Dek-Nil commanded them to promptly return to the jail. The three individuals returned to Accresker Jail, which then disengaged from the burning frigate.
Aphra was subjected to interrogation by an Interrogation officer and his Lieutenant, but their efforts proved unsuccessful. They planned to employ more effective methods to break her resolve. Upon Aphra's return to the other convicts, Lopset Yas presented her with a repaired transmitter. She utilized it to persuade Magna Tolvan to undertake her rescue. At that juncture, Accresker Jail was en route to Senex-Juvex as part of the Empire's bandit purges. As they engaged a pirate station, Tolvan attempted to rescue Aphra, but the Force-spirit once again thwarted their escape. While Aphra pursued it, Tolvan was attacked by Sana Starros, leading to the destruction of both of their ships. Aphra also discovered that the Force-spirit was, in reality, generated by some gundravian hookspores residing near a long dead Jedi. As the assault on the pirate station concluded, Aphra was escorted away by a hubdroid for further interrogation. There, she was questioned by Bor and compelled to reveal the presence of the hookspores. As a consequence, Accresker command resolved to decommission Accresker Jail and propel it towards a rebel planet.