Merlin': Ten more teasers about 'A Servant of Two Masters' 

Gwen and Gaius must team up to save the King but can Morgana's plot be foiled in time? Expect mercenaries, betrayal and an epic battle between two masters of magic on Saturday night - Merlin airs on BBC One at 7.55pm!.
Keywords: merlin, arthur, gwen, morgana, season 4