Seventeenth Master

The eighteenth incarnation of the Master.

Last Great Time War
Newly regenerated, the Master swore revenge on the Doctor and his companions, but ultimately his memory of Alice's intervention in the War was erased. (COMIC: Fast Asleep) The Master's TARDIS recorded that the Master fled the event horizon in his TARDIS before the Doctor's plans were carried out, deeming them too insane even for him. (COMIC: The One)

The Master fought the Supreme Dalek on the slopes of the Never Vault, (TV: The Witch's Familiar) and was present when the Dalek Emperor took control of the Cruciform. Frightened by the horror of the Time War, he ran away as far as he could, to the end of the universe, (TV: The Sound of Drums) where the Time Lords were forbidden to look. There, he used a chameleon arch to hide himself as a human named Yana. (TV: Utopia) Rassilon sent the War Doctor to find the Master, but he was unable to do so. (PROSE: Engines of War)

Under the chameleon arch
Physically human, Yana recalled that he was found as a naked child on the coast of the Silver Devastation with only an "heirloom" fob watch. His memory of his past was that the watch could never keep time and that he was always late for things as a result. He believed that he spent his life moving from one refugee ship to another and all his life he heard the sound of drums every waking hour as if they were getting closer.

Yana retained the Master's brilliant intellect and ultimately became involved in the attempt to send the remnants of humanity to Utopia. He eventually became friends with another scientist, Chantho, who was thought to be the last of the Malmooth race. Together, they worked on the Utopia Project to convey the surviving humans from the planet Malcassairo to Utopia.

Yana met the Tenth Doctor, Jack Harkness and Martha Jones when they were rescued from the Futurekind. Overhearing conversation between the Doctor and Jack about things such as time travel, Daleks, and regeneration, Yana became visibly upset. Martha drew Yana's attention to the watch in his possession and, hearing voices that commanded and entreated him, Yana opened the watch and returned to his true identity.

The Master then locked the Doctor out of Yana's lab, and opened the gate keeping the Futurekind at bay, saying to a shocked Chanto that "as one door closes, another must open". After Chanto threatened him with a gun, the Master electrocuted her with a loose set of power cables, angered that she was never curious of the fob watch during their decades of working together, and left her for dead. However, Chantho used the last of her strength to pull a laser gun on the Master while his back was turned, and shot him in the chest before she died.

Fatally wounded, the Master slithered into the Doctor's TARDIS while the Doctor watched on, deadlock sealed the door shut to keep the Doctor out, and regenerated into a younger body. (TV: Utopia)