In an alternative universe, a version of the Fourth Doctor fulfilled his mission to alter the creation of the Daleks. (AUDIO: Dust Devil)
Biography
The Fourth Doctor was sent by the Time Lords to prevent the creation of the Daleks (TV: Genesis of the Daleks). After he decided to go ahead with the mission, he witnesses the death of Sarah Jane Smith and Harry Sullivan by a prototype Dalek, before being brought back to Gallifrey, where Narvin assisted him in his regeneration into the Warrior. (AUDIO: Dust Devil)