Alliance to Restore the Republic's Ordnance and Supply Command put out an alert that the reserve of R2 units were dangerously low. In response the Rebels started a priority search for R2 units.
A previous scout mission located a freighter carrying R2 units had broken down with a failed hyperdrive system in the Rudrig system.
The Rebels sent 3 R-22 Spearheads from Red Squadron and a Lambda-class T-4a shuttle, Rescue Riker. The shuttle contained a boarding party to capture the freighter.
During the raid, an unknown group of pirates also made an attempt at the freighter and it's R2 units.
The Rebels obtained their much needed R2 units, however they turned out to be a plant by the Empire in an effort to capture personnel belonging to the Rebellion.
- X-Wing: The Official Strategy Guide
- Star Wars: Age of Rebellion Core Rulebook