Valeyard - in The Trial of A Time Lord

In The Trial of A Time Lord

The Valeyard appears in all four segments of Trial — The Mysterious Planet, Mindwarp, Terror of the Vervoids and The Ultimate Foe. In episode 4 of The Mysterious Planet it is stated that "valeyard" means "learned court prosecutor" in their language, although the term is obsolete and highly obscure.

During the course of the trial, the Doctor was accused of "conduct unbecoming a Time Lord" and transgressing the First Law of Time. As prosecutor, the Valeyard presented the events of The Mysterious Planet and Mindwarp as extracts from the Matrix, the computer network that serves as the repository of all Time Lord knowledge. The Valeyard used these extracts as evidence of the Doctor's meddling in time and space. Throughout the presentation of the evidence the Doctor barked at the Valeyard, calling him names such as "the Boneyard," "the Scrapyard," and "the Knacker's Yard," and only the interventions of the Inquisitor, another Time Lord, kept the trial going.

What was not discovered until later was that the Matrix extracts had been tampered with to show the Doctor in the worst possible light, the Doctor unable to directly contradict some of the actions shown as his own memory of the events depicted was hazy due to his extraction from time having disorientated his memory. In The Mysterious Planet this involved the editing of particular scenes. Scenes of the mercenary Sabalom Glitz attempting to buy "secrets" from the robot Drathro were censored completely. In Mindwarp substantial portions of the extract were falsified entirely by the Valeyard. The most significant alteration was when the Time Lords intervened in the brain transplant experiments of Lord Kiv and his scientist Crozier. In the Matrix extract, it appeared that Yrcanos was manoeuvred into killing the Mentors after Kiv's mind had been transplanted into the body of the Doctor's companion Peri – the Doctor having apparently betrayed Peri to save himself after exposure to one of the machines in the lab temporarily altered his personality – effectively killing her.

When the Doctor presented in his defence the future events of Terror of the Vervoids, he began to suspect that the Valeyard was tampering with the evidence – having reviewed the evidence before presenting it and noting some differences between what he had witnessed then and what was now being displayed – but lacked proof. The Doctor was shown being forced to destroy the human-plant hybrids known as the Vervoids when they ran rampant on a space liner. If they had been allowed to reach Earth they would have eliminated all animal life. The Valeyard argued that this meant the Doctor had committed genocide.

In The Ultimate Foe, the Master appeared in the Matrix, revealing that it was possible to infiltrate it. Sabalom Glitz and the Doctor's future companion Melanie Bush were presented to the Court to rebut the Valeyard's accusations. It was then revealed that the Valeyard was, in fact, the Doctor himself — or rather, a distillation of the Doctor's evil side, a potential dark version who might exist around his twelfth and final incarnation. This concept is similar to the ethereal "Watcher" that manifested itself to bridge the gap between his fourth and fifth incarnations (Logopolis). However, in the novelisation of the story the Master states "The Valeyard, Doctor, is your penultimate reincarnation... Somewhere between your twelfth and thirteenth regeneration".

The Valeyard was also revealed to be acting at the behest of the High Council of Time Lords to cover its corruption in the Ravalox affair. The "secrets" that Glitz had been seeking were information from the Matrix. Ravalox was Earth, but the Time Lords moved it through space, killing virtually every human being living on it. To prevent the Doctor discovering the secret and revealing it, they used the Valeyard to try to have the Doctor executed under the pretence of a trial. The reward for the Valeyard's actions would have been to give him all of the Doctor's remaining regenerations and make his existence concrete. However, the Valeyard would then have slain every member of the Court as well, using a particle disseminator located within the Matrix.

The Doctor entered the Matrix and fought and defeated the Valeyard in a fictional world of his creation. The Inquisitor revealed that Peri had indeed survived and was married to Yrcanos. The Master and the Valeyard appeared to be trapped in the Matrix, with the Valeyard apparently being destroyed by the feedback from the particle disseminator, but at the end of the serial, the Valeyard was seen disguised as the Keeper of the Matrix. The subsequent whereabouts of the Valeyard have never been disclosed in the television series.