Ars Opus was a BFF-1 bulk freighter that was carrying R2-series astromech droids to the Imperial-class Star Destroyer Invincible when it apparently broke down in the Rudrig system. The Ars Opus was discovered by a Rebel R-22 Spearhead reconnaissance flight and, following a recent warning from Ordnance and Supply about a shortage of astromech droids, the Rebels decided to mount a capture operation.
However, the carriage also lured pirates that attempted to hijack it and claim the units. A pirate force of transports and Y-wings battled briefly against Rebel R-22 Spearheads from Red Squadron led by Keyan Farlander. The Rebels were able to hold off the pirates while the crew of the Lambda-class T-4a shuttle Rescue Riker boarded and captured the freighter. More R-22s from Blue Squadron arrived to escort the newly captured freighter and the pirates were unable to get close enough to prevent its escape.
The Rebels later discovered that the Ars Opus and its cargo had been used as bait by the Galactic Empire as part of a plan to capture some Rebel X-wings and their pilots. The R2 units had been deliberately programmed to hijack any X-wings they were used in. Three X-wings from Blue Squadron fell into the trap and were hijacked during a mission.
The Rebels mounted a quick rescue mission to recover the stolen ships and their pilots before they could be delivered to the Invincible. Tracking the X-wings to the Invincible's location, three Y-wings from Red Squadron disabled them, allowing shuttles to deliver new R2 units and the pilots to take control of their ships and fly them to the waiting Mon Calamari Star Cruiser Maximus. Though two of the Y-wings entered hyperspace as soon as their targets were disabled, Keyan Farlander engaged TIE Series fighters launched from Invincible and protected the rescue of the pilots, including his friend, Hamo Blastwell. The remaining R2 units were later wiped clean before use.