Mook Jayasundera was a parallel universe counterpart of N-Space's Mook Jayasundera. He encountered Rose Tyler when he was concerned about his grandfather Roni Bandara's health after hearing that he might commit suicide. He then went with Rose to get more medicine for him when they realised his inhaler was nearly empty. He was in love with Patrice Okereke and had to tell his grandfather this regardless of what he thought. (AUDIO: The Last Party on Earth)