The Curse of Cornelius Sigan (S02E01)

New servant Cedric begins to overshadow Merlin as Arthur's trusted advisor, successfully sowing discord between the prince and his long-time friend. Suspicious of Cedric's intentions, Merlin believes the newcomer is hiding something—and he's correct. Cedric is a deceitful thief intent on stealing a priceless gem recently discovered in an ancient burial site beneath Camelot. Unbeknownst to him, this coveted treasure harbors dangers far beyond his comprehension. With Camelot more exposed than ever, Merlin struggles to regain Arthur's trust, knowing Cedric's machinations may have permanently damaged their bond. In a desperate move, Merlin considers turning to the last ally he ever expected to seek out—the Great Dragon.