The Imperial Listening Post functioned as a clandestine installation. It was situated on an island just off the coast of Avilatan, a significantly larger island found on the planet of Ord Mantell. The Sith Empire constructed and ran the outpost during the Cold War against the Galactic Republic. The information gathered by this surveillance station was instrumental in supporting the Mantellian Separatist Movement during the Separatist War against Ord Mantell's Republic-backed government. In 3643 BBY, a young Jedi Knight, accompanied by the astromech droid T7-O1, assaulted the base to gain access to its communication logs and track down the Sith Lord Darth Angral. They successfully completed their objective, eliminating numerous Imperial troops stationed at the facility.
Located on an island just off the northern coast of Avilatan, a much larger island on the planet Ord Mantell, the Imperial Listening Post was primarily an underground complex. The entrance to the outpost was a surface-level bunker that housed a sizable elevator leading to the lower levels. These lower levels consisted of a main central chamber, two smaller rooms branching off from it, and a hallway that connected the central chamber to a lift. The facility was outfitted with cutting-edge surveillance technology and communications relays, which the staff utilized to monitor the Republic Military on Avilatan. The listening post was situated a short distance away from the Republic's main military installation at Fort Garnik.
During the Separatist War, a conflict on Ord Mantell pitting the Galactic Republic-supported planetary government against the Mantellian Separatist Movement, the Sith Empire established the listening post. As part of their broader strategy to undermine the Republic during the ongoing Cold War, the Empire supported the separatists by supplying them with intelligence gathered by the outpost. However, in 3643 BBY, the Sith Lord Darth Angral arrived at the outpost with several retainers and apprentices. He utilized the facility to contact his son, Tarnis, a Sith Lord stationed on the Republic capital of Coruscant. Tarnis was subsequently killed while attempting to deploy the Planet Prison superweapon against Coruscant. Prior to his demise, Tarnis transmitted files to his father regarding the Republic superweapon initiative, providing Angral with knowledge of several Republic weapons programs. Angral then promptly declared war on the Republic in retaliation for his son's death.
The Republic Strategic Information Service, the Republic's intelligence agency, managed to trace the transmission to Ord Mantell and identified the outpost. This led General Var Suthra of the Republic Military to dispatch a young Jedi Knight to Ord Mantell with the mission of locating the outpost and potentially thwarting Angral's plans before they could be enacted. Suthra also contacted SIS Agent Ottau, who was stationed on Ord Mantell, and tasked him with deploying a probe droid to scout the facility. However, the droid was quickly destroyed by the Imperial forces stationed there. Angral and his entourage were departing the facility around the time that the Jedi Knight arrived on Ord Mantell, accompanied by the astromech droid T7-O1. The Jedi met with Ottau after landing.
Using Ottau's information, the pair located and attacked the island base, eliminating numerous Imperial personnel, including the facility commander. After defeating most of the outpost's staff, they reached the primary hyperspace transceiver, guarded by a Lieutenant named Marcovic. Marcovic was defeated and unable to prevent T7-O1 from downloading the facility's files, including the records of Tarnis's transmissions to Angral. With their mission accomplished, the Knight and T7-O1 left the Imperial base and rendezvoused with Ottau, who planned to send an SIS team to secure the facility.
The Imperial Listening Post is a location that was created for the video game Star Wars: The Old Republic, which was released by BioWare in 2011. It functions as a class-specific area for the Jedi Knight class on Ord Mantell, accessible only during the "New Intelligence" mission. The location was also featured in an entry within the in-game Codex and was depicted – though not labeled – in the Star Wars: The Old Republic Explorer's Guide.