The Lost Boy (2) (S01E10)

Maria and her father, Alan, delve into the unsettling truth about Luke's new parents and uncover that he has been taken by the Slitheen. The situation worsens when Sarah Jane and Maria realize that Mr. Smith, Sarah Jane's advanced computer, is actually in league with the villains. With Clyde mysteriously absent, Luke trapped by aliens, and Mr. Smith unavailable, Sarah Jane and Maria find themselves in a dire predicament. They are left questioning the Slitheen's intentions regarding Luke and the identity of the enigmatic Xylok.