The fifth episode of Merlin Secrets and Magic focuses on the character of Lady Catrina, and what it takes to turn into the troll who is able to soften Camelot king's heart as explained by Sarah Parish herself, who unmasks the secrets behind the incredible prosthetic make-up job. It also goes behind the scenes to offer exclusive backstage footage, production details and on-set cast and crew interviews from the filming of Merlin's episode 2x05 Beauty and the Beast – Part One.