Newly crowned Queen Catrina (Sarah Parish) settles in as Camelot’s first lady. As her true troll nature surfaces her influence over King Uther increases and the repercussions are felt throughout the kingdom.
When Catrina accuses Merlin of stealing, he is driven into hiding. Forced to sneak around the castle, Merlin must find a way to expose Catrina’s true form without getting caught – and beheaded. But even if he succeeds, will this be enough to break her powerful magic? Or will Camelot be stuck with a troll as a Queen forever?