During the Battle of Geonosis Grimes lead his squad Aurek against the legions of battle droids. After helping clear the arena, Grimes sent the rest of his squad to help another platoon . As the dropship took off, Grimes watched as it was struck by an anti-air round and exploded into a fireball. After witnessing the destruction of his entire squad, Grimes wandered the Geonosian Arena killing droids in a dismal fog. While wandering Grimes ran into CT-3107, the second in command of his squad. Apparently he hadn't gotten onto the dropship because he had his helmet damaged an was looking for a replacement.