Turn Left (Doctor Who) Turn Left (Doctor Who) "Turn Left" is the eleventh episode of the fourth series of British science fiction television series "Doctor Who". It was written by showrunner Russell T Davies and broadcast on BBC One on 21 June 2008. David Tennant only makes a small contribution to this "Doctor-lite" episode as the Tenth Doctor. The story instead focuses on the Doctor's companion, Donna Noble (Catherine Tate) and her encounters with former companion Rose Tyler (Billie Piper). The episode's narrative focuses on an alternative history where the Doctor dies during the events of the 2006 Christmas special "The Runaway Bride". The
Doomsday (Doctor Who) the alternate universe Pete Tyler, who tells him that after he left the Cybermen were sealed in their factories while humanity decided what to do with them. In the meantime, the Cybermen vanished and the breach began causing unprecedented global warming on the parallel Earth, which the Doctor theorises is the start of the process that will lead to both planets falling into the Void. Pete demands the Doctor seal the breach before his Earth is destroyed. Meanwhile, Rose deduces that she and Mickey were kept alive because their touch can activate the Genesis Ark. Dalek Sec explains that they