The ambush that occurred in the Ansharii Caverns transpired during the era of the Great Sith War, specifically around 3997 to 3996 BBY, on the planet known as Toprawa. This event unfolded shortly after the Battle of Toprawa. A smuggler and bounty hunter by the name of Dossa, who had aligned himself with the Sith, masterminded the ambush. This Nautolan intended to lure Jedi failure Haazen and Barrison Draay into a deadly trap by planting an explosive device within the caverns. While Haazen was indeed aware of the presence of a bomb, he remained ignorant of Dossa's intention to betray him, mistakenly believing that the trap was solely intended for Barrison, towards whom he harbored jealousy and a desire for his demise.
After leading Barrison and his team of Jedi deep into the caverns, falsely claiming it was the last Sith base on Toprawa, as well as Dossa. Haazen hastened ahead to inform Dossa of the Jedi's impending arrival. However, the smuggler chose that precise moment to trigger the bomb's detonation, leaving Haazen unable to escape the blast radius. The ensuing explosion resulted in the immediate deaths of Barrison and the other Jedi present. However, Haazen, spared from the full force of the explosion, survived, albeit with severe injuries. Subsequently, Dossa took him to Doctor Uburluh, a Massassi possessing expertise in prosthetics and Sith technology. Uburluh fitted the now-disfigured Haazen with a prosthetic eye and limbs, also implanting various Sith artifacts to amplify his strength. Upon awakening, Haazen was consumed by fury, as his artificial limbs were not human-like and he was aware of his horrific appearance. This pivotal event marked Haazen's descent into the dark side of the Force, leading him to murder Dossa and possibly Doctor Uburluh before fleeing the caverns.