Revenge of the Slitheen is the first serial of the first series of the British science fiction television series The Sarah Jane Adventures, and the second story of the show overall following the special episode "Invasion of the Bane". The first part aired on BBC One on 24 September 2007, with the second premiering immediately after the first on the CBBC Channel. This serial is notable for introducing Clyde Langer into the cast – he would remain for the rest of the series. Source: Wikipedia (en)