The Chiss Ascendancy's Senior Captain Mitth'raw'nuruodo embarked on a mission to the Rapacc system. This was prompted by the discovery of a refugee starship's destroyed remains within Chiss space, the ship having been attacked by the Nikardun Destiny. Thrawn traced the ship's origins to the Rapacc system after finding a second abandoned vessel. With the aid of Admiral Ar'alani and the Vigilant, Thrawn skillfully piloted the heavy cruiser Springhawk into the system. He then boarded a deserted mining station alongside the caregiver Mitth'ali'astov. The Nikardun, detecting the Vigilant's presence, dispatched enslaved Paccosh to infiltrate the station. Thrawn engaged in conversation with the Paccosh, uncovering the identity of the Nikardun and their commanding General, Yiv. The Paccosh, rather than reporting him to the Nikardun, allowed Thrawn to depart, enabling him to continue investigating Nikardun activities.
During their time on the asteroid mining station, Thrawn and Thalias encountered Uingali foar Marocsaa, the Paccosh leader. Uingali gifted Thrawn a double ring that featured a chimaera. This chimaera design would later become Thrawn's personal symbol and the namesake of his flagship when he served as an officer in the Galactic Empire.
Four and a half months subsequently, amidst the Nikardun campaigns, Thrawn, Thalias, and the Springhawk returned to the Rapacc system in search of lingering Nikardun forces. While there, Thrawn gave the Marocsaa subclan ring back to Uingali and also came across the Magys' leader, a group of refugees.