In the year 3 ABY, Sly Moore, an Imperial Sub-Administrator, conspired with members of her court. Their objective was to assassinate the Sith Lord Darth Vader and replace him as the right hand of the Emperor Sheev Palpatine with the rebel pilot Luke Skywalker.
To prepare for her initial attempt, Moore, recently demoted from Administrator to Sub-Administrator following her failure to eliminate Vader at Palpatine's command, obtained the schematics of Vader's armor. She then provided these schematics to the bounty hunter IG-88, who subsequently encountered Vader in Zee-Nine City Seven within Hutt Space. IG-88 nearly caused the Sith Lord to inadvertently decapitate himself. However, Vader ultimately used the Force to seize a controller held by the droid containing the armor's control codes, turning IG-88 against himself and forcing the droid to shoot himself in the head. Sometime later, IG-88, having rebuilt himself, journeyed to Coruscant to meet with Moore and her court, informing them of his decision to terminate the contract, believing Vader to be undefeatable.
However, Vader had been tracking the bounty hunter, and struck down the droid for a second time. The court cleared the way to a nearby temple, where Moore, similarly to IG-88, employed a remote to freeze Vader's armor, intending for her court to kill Vader. The assassins were unsuccessful in their attempts as Vader had the vulnerability fixed. Vader knocked the remote out of her hand as he told her that she could not bend the will of a Sith. Moore responded that she had only wanted to see if Vader was plagued by fear, before adding that whilst he could easily kill her, it would not save him from him being replaced by Skywalker in the favor of Palpatine. Moore then suggested bidding for the carbonite-encased body of Han Solo at Crimson Dawn's approaching auction. This was so Vader could use Solo as bait to draw in and eliminate Skywalker, a plan Vader accepted, unaware of Moore's true motives. Moore further stated her eagerness to unite Vader and Skywalker, considering the young rebel the only one capable of defeating Vader.
Moore was present at the auction, but Jabba Desilijic Tiure outbid her, winning the prize. Soon after, Vader appeared and claimed Solo for himself, with Jabba eventually relinquishing Solo to Vader and the Empire. As planned, Vader used Solo as bait to attract Skywalker, threatening to bisect Solo if Skywalker refused to come to him. Skywalker, unable to confront Vader directly, opted to distract Vader in his X-wing long enough for Leia Organa to retrieve Solo for the Rebel Alliance. Vader fell for the ruse and pursued him in his TIE Advanced. While the two engaged in a chase above and within the skies of Jekara, Moore directed the Droid Crush Pirates of Bestoon to assassinate Vader, hoping to facilitate Skywalker's escape. This action revealed her true scheme to Ochi, who, after a duel, apprehended Moore, thus ending her plot to kill Vader.