At that moment, Grievous' fleet is advancing on his. Plot summary īecause General Grievous has been ambushing Republic fleets, Obi-Wan Kenobi advises that Anakin Skywalker take his fleet out of the Bothawui system and regroup, but Skywalker has a plan to defeat Grievous. R2-D2 is lost during a fierce space battle - and Anakin, along with Ahsoka and a replacement droid, R3-S6, must find him before the Separatists discover the Jedi military secrets locked in his memory banks.