Dr Will Sullivan was the stepbrother of Harry Sullivan.
He wanted to know what had happened to him. (AUDIO: Buried Secrets)
He invited Sarah Jane Smith to visit Antarctica but then told her not to go. (AUDIO: Snow Blind)
He was a member of the Crimson Chapter of the Orphans of the Future. He was recruited whilst as a student as he thought it was just a student society. He was killed by Josh Townsend after he tried to kill Sarah Jane Smith. (AUDIO: Fatal Consequences)