The Arrth-Eno Prison, also known as the Arrth-Eno Custodial Complex, was a large prison on the planet Coruscant. During the Galactic Civil War, the Galactic Empire housed former members of the Imperial Senate who were loyal to the cause of the Alliance to Restore the Republic. Darth Sidious destroyed the prison as part of a trap to execute the senators and a group of Rebel spies, events that he blamed on the Rebellion.
The senators sentenced to death held in a cell on Arrth-Eno
The Arrth-Eno prison, officially referred to as the Arrth-Eno Custodial Complex by Galactic Emperor Sheev Palpatine was a Imperial prison complex located on the capital planet Coruscant, on a vast empty clearing amidst the Imperial City. It was housed in a tall tower surrounded with golden balconies and capped with a similar-looking structure which included hangar bays for transports servicing the facility. The base of the tower didn't actually touch the ground, rather being supported by multiple blade-like protrusions, and the tower walls were lined with large exhaust ventilators, which however were weak points of access as they could be shattered and used for entry to the prison's ventilation shafts. There were also secretly explosive charges running the height of the tower which could be used to swiftly obliterate the entire structure.
The complex included several small cells with four beds each, which could be completely sealed and isolated from the corridors. A comms room staffed by four communications officers and including wall-mounted computers and a holoprojector was located near the cells and could be used to send and receive coded messages.
The very top of the tower consisted of a massive throne room for Emperor Palpatine to meet with and talk to prisoners, and was decorated with the Imperial crest. A golden repulsorlift-equipped throne could be placed in a platform the center of the room, directly underneath a ceiling hatch; in case of an emergency, the throne could swiftly take off to carry Palpatine to a shuttle landing bay waiting to evacuate him on the roof.
In 0 BBY, following the dissolution of the Imperial Senate by Emperor Palpatine, all Senators were arrested and dispatched to the Arrth-Eno complex to evaluate the degree of cooperation each one shared with the Alliance to Restore the Republic. According to Admiral Garrick Versio, those included Senators who had served in the body in the past.
Eneb Ray was living in Coruscant as a deep undercover Rebel agent
Sometime later during that year, the evaluations were complete and less than 20 Senators remained imprisoned in the complex. Those were believed to have cooperated with the Alliance fully, and thus were secretly sentenced to death. To avoid the public uproar that would have resulted from an officially sanctioned execution, however, Palpatine devised a plan to pin their deaths to the Alliance. As such, he leaked the location and planned fate of the Senators to the Rebels through officer Coleet who worked at the complex, prompting the Alliance to task one of their agents on Coruscant, Eneb Ray to rescue them from captivity. The Senators had however been told that they would meet with Palpatine an hour later, and revealed this information to Ray, who changed his plan and infiltrated the prison communications room to notify Princess Leia Organa of this development.
Palpatine deflects the blaster bolts fired by Ray
While detaining the communications officers in the room, one of them, Coleet, broke her cover and revealed that she was the mole. Ray and Coleet contacted Leia, who gave them permission to move forward with an assassination attempt on Palpatine; she also revealed the identifies and contact of all seven Rebel undercover agents on the capital, to assist them with the attempt. Dressed as the Senators, the seven infiltrators were led before Palpatine, who greeted them warmly, before they opened fire, killing his stormtrooper guards and engaging the Emperor's Royal Guard. Ray attempted to shoot Palpatine, with "the complements of Alderaan," but Palpatine's throne took off through the roof to lead him to a waiting evacuation shuttle.
Ray followed suit with a grappling hook attached to the throne, and shot the man before he could board the shuttle. However, the real Emperor emerged from the starship, revealing that the one Ray had shot was an good body double. Ray, perplexed with Palpatine's decision to come to what he knew would be a Rebel attack himself, grabbed onto the shuttle ramp and attempted to shoot the real Palpatine, but he blocked the shots through the Force and instructed Ray to look behind him, as the Complex's charges detonated, killing all rebel spies and sympathetic Senators. Palpatine then unleashed Force lightning against Ray, who fell from the shuttle, but was saved at the last moment by using his grappling hook to cling on to a speeder.
Soon after the Complex's destruction, Palpatine addressed the citizens through the HoloNet, revealing that it was the result of a Rebel attack, and claiming that the Senators held inside would be taken to a fair trial to reveal their connections with the Alliance, but were assassinated by their handlers so as not to reveal any sensitive information. Palpatine promised a swift response to the heinous Rebel attack, having eliminated all undercover agents within his capital as well as the dissident Senators. Eneb Ray was broken physically as well as psychologically from this incident and Palpatine's total victory, and sometime later during this year gathered a group of IG-RM bodyguard and enforcer droids to attack Sunspot Prison, which held Imperial criminals arrested by the Rebel Alliance. There, he began executing them one by one, until Leia and Sana Starros managed to stop him.
- Star Wars: The Rebel Files
- Star Wars: Timelines
- Star Wars: The Rise and Fall of the Galactic Empire