S2, E5: The first episode of this exciting two parter sees Uther captivated by his latest guest, the beautiful Lady Catrina (Sarah Parish). Arthur is appalled by his father’s flirting but Merlin’s wary for a different reason – he suspects she is really a troll! Catrina and her strange servant Jonas (Adam Godley) are welcomed into the heart of Camelot and it is up to Merlin to prove she’s a monster and save Uther from ruin. Unfortunately, Catrina has her sights set on a far greater prize than the King’s heart. Can Merlin overcome her powerful troll magic before it’s too late?