Trial of the Valeyard ( audio story ) Trial of the Valeyard was the eleventh and final subscriber - exclusive release from Big Finish . It acted as a sequel to the events of " The Trial of a Time Lord " with a karmic reversal of who was on trial , and featured Michael Jayston ' s latest return to the role of the Valeyard since his last appearance in the 2003 audio release " He Jests at Scars . . . " . The audio also offered a potential explanation regarding the unknown origins of the Valeyard , but did not confirm any statements in the account given about his past as undeniably true . Publisher ' s summary . There is some evil in all of us — even the Doctor . Transported aboard the Time Lords ' orbiting courtroom , the Doctor once again encounters the Valeyard , an amalgamation of the darker sides of his nature . This time , however , the Doctor isn ' t in the dock . This time , the Valeyard is the defendant , accused of a crime so terrible that the presiding Inquisitor is forbidden to reveal it even to the court , nor even to his counsel for the defence . . . the Doctor . If the Valeyard is found guilty , he ' ll be executed . Execute the Valeyard , and the secret of his origins dies with him . A secret that the Doctor is desperate to know . . . and which the Time Lords will stop at nothing to protect . Plot . The Doctor is abducted by the Time Lords into a space station above the gas giant Etarho , where a court will be called in session . The Doctor initially refuses to take part in the proceedings , but in finding out that the defendant is the Valeyard , and being told by the Inquisitor that Valeyard has named him as his solicitor , he stays to defend the Valeyard due to his curiosity . The Doctor is at first determined to find the Valeyard guilty , but the situation becomes even more complex as history is rewritten and information becomes classified as the court session goes on . After counselling the defendant , the Doctor agrees to defend the Valeyard due to the Valeyard " being clever " . The crime of which the Valeyard is accused , trivial hacking on to the Matrix , bewilders the Doctor . In response , the Valeyard tells about his past , explaining that when he was a mere twenty years old , he was found on the mud - moon orbiting Etarho by prospectors , who , upon finding out he was a Time Lord , took him to Gallifrey . When examined there , his biodata was apparently found to be the same as the Doctor ' s , and he was therefore considered a temporal abnormality by Time Lord society and placed in a Shadow House . In the Shadow House the Valeyard met a Time Lord who had been damaged due to temporal interventions by his future self and therefore had his regeneration permanently stuck in a paradox . The man told the Valeyard to study the science of regeneration , in order to gain revenge on the Time Lords for what they had done to every member of the Shadow House . The Valeyard decided to follow the advice , and claims to have made many interesting discoveries during his studies and even voices the heresy that Rassilon himself imposed the fatality in the thirteenth regeneration to keep the Time Lords in check . The Valeyard then claims that he was the result of illegal experiments made by the Thirteenth Doctor on the mud - moon . Evidence of the experiments , the Doctor ' s Black Scrolls , were apparently in a container still on the planet . The moon is translocated by the Time Lords in order to erase the evidence presented . After some commotion , the Valeyard is found guilty by the Inquisitor and sentenced to termination , which is to be carried out immediately . The Valeyard gloats one last time as he is executed in front of the Doctor , claiming that by witnessing this event the Doctor is now irrevocably on the path to eventually become him . Deeply disturbed , the Doctor leaves the court . The Doctor tracks the displaced timeline containing the mud - moon and finds the supposed thirteenth , mad incarnation of himself , in a shack like the one the Valeyard described . He tries to get some answers from the rambling lunatic , but he is interrupted as several military TARDIS arrives , and he realises that the Inquisitor accompanied a squad of guards has followed him to the moon . The Thirteenth Doctor is startled by their arrival , and runs out into the mud as the forces close in , but gets stuck in a mud hole and starts sinking down , and despite the Doctor ' s attempt to save him , he goes under . The Inquisitor explains to the that the Time Lords ransacked the supposed laboratory some time ago and came across a mysterious container , which they believe contains the Black Scrolls . They found that only the Doctor ' s biodata could open it , and therefore they went to the Valeyard first , but he refused to help them opening it , and the Inquisitor now begs the Doctor to open the container for them . The Doctor deduce s that the actual reason the Valeyard was put on trial was because he refused to reveal the supposed secret of immortality in those scrolls . He then deduce s that the container does not actually contain the scrolls , but a bomb set as a trap by the Valeyard and that the Thirteenth Doctor is actually the Valeyard in disguise . The Valeyard then emerges from the mud , and reveals that he faked his execution by placing a Matrix door under the dock , and that he cooked up the whole scheme with the fake Black Scrolls in an attempt to get to get revenge on the Doctor and the Inquisitor . He then activates the countdown on the bomb before escaping through a Matrix door hidden in the mud . The guards flee , and the Doctor and the Inquisitor escape aboard his TARDIS before the bomb explodes . The Doctor returns the Inquisitor to the courtroom . There they discuss the Valeyard ' s scheme , and the Doctor warns the Inquisitor that the Valeyard will likely attempt to extract revenge on them again , and that he probably had help from someone inside the Time Lord council , pointing out that it would have been nearly impossible for him to sneak a Matrix door into the court on his own . The Inquisitor wonders what could have motivated someone to help the Valeyard , and the Doctor notices that while he believes that most of the Valeyard ' s claims about his discoveries in the study of regeneration were fiction , he thinks that can still have been a grain of truth to them , and even a fleeting promise of immortality can have been enough to tempt a powerful Time Lord with unfulfilled ambitions and the end of their regeneration cycle closing in . The Inquisitor promises to launch a full juridical inquiry into the matter , and the Doctor says he would expect nothing less from her , before taking his leave .