In 20 BBY, the Jedi Order undertook a mission to recover the Galactic Republic's secret battle plans, which Chancellor Palpatine had given to Separatist General Grievous to take to the planet Geonosis. During the mission, R2-D2 fell into the droid factory's gear system, which jammed and blew it up.
During the Clone Wars, Chancellor Palpatine stole Republic Battle Plans and presented them to General Grievous with the task of delivering them to the Separatist Council.
- LEGO Star Wars: The Official Stormtrooper Training Manual