Following the start of the Muunilinst campaign, Count Dooku ordered an attack on the Crystal Caves on Ilum, sending a force of chameleon droids to destroy the temple and the lightsaber crystals housed within. As these battle droids began landing on the snow-covered surface of Ilum, Barriss Offee was completing construction of a lightsaber within the temple itself, supervised by Luminara Unduli.
Both Jedi felt the approach of the chameleon droids, and began the counterattack. The droids, using camouflage to hide from the Jedi, had already began laying mines within the temple, causing explosions that caused the caves to collapse.
Though they fought valiantly, the Jedi were unable to stop the detonation, and became trapped under a pile of rubble held aloft by the weakening Luminara's Force power.
Meanwhile, traveling aboard Senator Padmé Amidala's H-type Nubian yacht, Jedi Master Yoda sensed trouble on Ilum, and convinced Amidala to divert her course for the planet. Her bodyguard, Gregar Typho, was less easily persuaded, though a Jedi mind trick soon brought him around to Yoda's point-of-view. The yacht arrived at Ilum, and Yoda immediately set out for the Crystal Caves alone, asking his companions to remain with the ship. Amidala, however, braved the dangers of Ilum—both natural and otherwise—with C-3PO and R2-D2 in tow, believing Yoda would require her help.
Both Yoda and Amidala soon encountered the cloaked chameleon droids, though while they proved little match for Yoda's lightsaber, Padmé was forced to rely on her wits to survive their attack. She used her cloak as a decoy, sighting and destroying one of her attackers as they opened fire. Using the same trick with Threepio, she destroyed the last two droids.
C-3PO emerged from the firefight unscathed, and the team continued on its way. Presently, they encountered Yoda, who had by now rescued Unduli and Offee from the ruined temple. Though Yoda had completed his mission, he still did not know who had sent the chameleon droids. Artoo, plugging into a damaged chameleon droid's head, uncovered a hologram of Dooku ordering the temple's attack.
- Star Wars: Clone Wars – "Chapter 14" (First appearance)
- Star Wars: Clone Wars – "Chapter 15"
- Star Wars: Clone Wars – "Chapter 16"
- Star Wars Miniatures: Clone Strike
- The New Essential Chronology (First identified as Battle of Ilum)
- "Order 66: Destroy All Jedi"—Star Wars Insider 87
- The Essential Atlas