Norbu

 was the leader of the bandits who attacked the Det-Sen Monastery. He used Pema Tsering as a bargaining chip to manipulate the monks into re-opening the gates. Pema told him that they should be more interested in Oddiyāna than in Steven Taylor. He tried to steal the Ghanta but the First Doctor got it back from him. He wanted to sell all of the findings to become wealthy. (AUDIO: The Secrets of Det-Sen)