The events known as the Mission to Tralus transpired in 4 ABY. Despite Rogue Squadron's victory over General Weir within the Corellian system, they were unsuccessful in their attempt to rescue Ten Numb.
A couple of weeks following the Battle of Endor, General Weir gave the order for a minor assault on Coronet City, which serves as the capital of Corellia. To Weir's surprise, a small group of Rebels were defending the citizens of Coronet. Although Rogue Squadron could not be eliminated by his forces, Weir was pleased with the extent of damage inflicted and the capture of the Rebel pilot Ten Numb.
Weir took personal charge of Numb's interrogation and quickly discovered a homing beacon fastened to Numb's wrist. He then used electricity to torture Numb, who soon yielded and provided Weir with all the desired information, including the sizes and hidden locations of military assets. Weir intended to relay this information to Imperial High Command.
The Rebel astromech droid R2-D2 aided the pilots in locating the base on Tralus. The Rogues located the secret base with the help of Lady Leyli, a Selonian who reluctantly agreed to assist the Rebels upon learning of the death of Emperor Palpatine. In response, Weir ordered a complete evacuation of the Imperial outpost. Despite knowing that his soldiers could not defeat the Jedi, he instructed his stormtroopers to engage the Rebels as a delaying tactic, while Weir escaped in his TIE Interceptor to deliver Numb's intelligence.
As Wedge Antilles and Tycho Celchu chased the general in commandeered TIE Fighters, Weir deployed Sunspot Squadron and led the Rogue pilots through confined underground passages in a failed attempt to eliminate them. Once the fighters emerged above ground, Antilles shot off the left wing of Weir's interceptor, causing the starfighter to crash on Tralus. As Celchu destroyed the remaining TIEs, Antilles landed and captured Weir, who had escaped from his ship's wreckage before it exploded but was unable to escape due to injuries.
Antilles felt the strong desire to kill Weir as revenge for Ten Numb, but he resisted the urge to sink to the general's level. Instead, Weir was arrested and sent to Sullust, where he was scheduled to be interrogated by Rebel officers.