Fan Casting Doctor Who American 4th Doctor (1974-1978)

In his new incarnation, the Doctor is eager to leave Earth in favour of exploration, thus drawing back from continuous involvement with UNIT (with which he had worked closely as the Third Doctor). He has also grown tired of working for the Time Lords. Despite attempts to avoid them altogether, the Time Lords continue to send him on occasional missions, including an attempt to prevent the creation of the Daleks (Genesis of the Daleks), during which he also meets Davros.