himself over the Doctor's timeline with the goal that he will then spread throughout the Matrix and replace all other Time Lords, the remnants of the Doctor's psyche in the Matrix after his 'death' are able to undo the Valeyard's attack by reaching back into his past and prompting his past self to set a course that will expose the TARDIS to a dangerous form of radiation, causing the Sixth Doctor to regenerate and thus purging his body of the Valeyard's influence, leaving his foe trapped in the Matrix as his victory is erased (The Brink of Death). The Valeyard returns in the third volume of The Time War, chronicling the Eighth Doctor's experiences during the Time War, when the Valeyard returns to existence as the Time Lords attempt to recruit him to act for their side in the War. As explained in the audio The War Valeyard, rather than coming from the Doctor's future, this version of the Valeyard is 'extracted' from the Doctor when he used a transmat after assisting another Time Lord on a mission involving exposure to a device that could manipulate biology, with the Time Lords deciding to utilise the Valeyard as a soldier in the Time War as he retains the Doctor's guile and intelligence without his morality, willing to carry out missions that would endanger planets and civilians that the Doctor would reject. Eventually, the Time Lords sent the new Valeyard to investigate a Dalek weapon that is supposedly capable of erasing the Time Lords from history. However, when the Valeyard attempts to turn the weapon on the Daleks, the Time Lords are forced to trap the planet in a time loop as the weapon's side-effects cause a small army of Daleks to still exist on that planet even after the Daleks themselves have been erased. His memory damaged by the weapon, the Valeyard comes to believe that he is the Doctor, fighting the illusionary Daleks created by the weapon's destruction. The Eighth Doctor briefly penetrates the time loop to investigate the Valeyard's existence, but accepts the Valeyard's request to remain on that world so that his other self can continue to believe he is the Doctor fighting the Daleks in a simpler conflict. List of appearances Television The Mysterious Planet Mindwarp Terror of the Vervoids The Ultimate Foe Novels Mission: Impractical (behind the scenes; does not explicitly appear) Millennial Rites (his dormant