"Hell Bent" is the twelfth and final episode of the ninth series of the British science fiction television series Doctor Who. It was first broadcast on BBC One on 5 December 2015. In the episode, the alien time traveller the Twelfth Doctor (Peter Capaldi) arrives on the planet Gallifrey after escaping imprisonment by his people, the Time Lords, and takes over as the new President. He tries in vain to use knowledge of "the Hybrid", which is prophesied by the Time Lords to stand in Gallifrey's ruins and unravel the Web of Time, to save the life of his companion Clara (Jenna Coleman). Doing so causes the Doctor and Clara themselves to become the Hybrid. This episode is Coleman’s final regular appearance as a companion.