Arthur is pressured into an arranged marriage with a visiting princess, Elena, but Merlin has his doubts when he discovers Elena may not be exactly who she claims to be.
Elena’s nanny Grunhilda (Miriam Margolyes) appears to be a slightly cheery old woman who took a liking to Gaius and was always flirting with him. She appeared to care for Elena and acted as her mother figure, but she too has a secret. Her true form is a repulsive, warty pixie who is working to help a Sidhe elder take over Camelot by possessing its future Queen.
Su Westwood was the makeup supervisor; Mark Coulier was the prosthetics designer; Victoria Bancroft & Sarah Lockwood were the prosthetics makeup artists.