Governor Koong's plan to use germ warfare on the province of Umboo backfires when he becomes infected with Rooze himself. Healer Nilz Yomm is desperate to find a cure for his wife Bola, but he and his daughter Auren are abducted by Gaff to cure the governor. Mungo and the droids travel to Koong's frozen hideout to rescue the Yomms and manage to solve the last clues to find the source of the Roonstones in the process.