In the year 52 BBY, Darth Plagueis, along with his two Sun Guards and 11-4D, found themselves under attack by Maladian assassins. This assault occurred while Plagueis and other Muuns were present at the initiation ceremony of Larsh Hill into the Order of the Canted Circle. The location was the Order's Lodge, situated within the Fobosi District on the planet of Coruscant. Palpatine and Sate Pestage subsequently arrived to provide assistance to Plagueis; however, by that time, only Plagueis and 11-4D remained standing, aside from the Maladians, who were quickly eliminated by Palpatine and Pestage using a Repeating blaster cannon. Due to the severity of his wounds, Plagueis was thereafter compelled to use a transpirator.
Following the conflict, two Jedi Knights arrived at the site, responding to the disturbances in the Force caused by the battle. They proceeded to inform the Coruscant Security Force about the situation. The Maladians' remains were so dispersed that the CSF detectives initially suspected an explosion, although they found no supporting evidence. The Jedi declined to explain their interest in the case or their presence at the location to the police. Later on, the CSF attributed the widespread destruction to a hit carried out by organized crime.
The Attack on the Lodge of the Canted Circle was initially envisioned by Star Wars creator George Lucas during the early planning phase of the 2012 novel Darth Plagueis, around the late 2000s. One of the pieces of information Lucas shared with James Luceno during the early stages of the project was that Plagueis should be a Muun, and also that Plagueis would wear a transpirator as a consequence of an assassination attempt on his life.