It was believed that Niroc oversaw or took part in Operation Ravolox and had purposefully put the Doctor on trial to prevent the truth from coming out. His High Council enlisted the Valeyard, a future manifestation of the Doctor's evil side, to act as prosecuting attorney and present fake evidence at the trial. In return, the Valeyard would receive the Doctor's remaining regenerations. (TV: The Trial of a Time Lord, PROSE: The Eight Doctors)