Merlin is told by the Great Dragon that it is his destiny to make sure that the young Prince Arthur is kept safe. Anybody caught performing magic is punished with death and Merlin is not a fan of Arthur. When Arthur's life is endangered Merlin finds himself tested.

Camelot is hosting its annual sword tournament and knights from throughout the realm have come to compete for its coveted title. Amongst those hoping to win the crown is Knight Valiant.

A deadly plague spreads through Camelot. When it seems that sorcery can be the only possible explanation, Merlin and Gaius race to find a cure, while Gwen is arrested and sentenced to death for practising witchcraft.

With her sights set firmly on Merlin, Nimueh tricks him into drinking from a poisoned chalice, and he falls dangerously ill. Arthur ventures forth deep into the forest of Balor to find the antidote, but little does he know that he's walking into a trap

Merlin is saved from a terrifying winged beast by a heroic stranger- a young man named Lancelot, who dreams of becoming a Knight of Camelot. In order to thank him, Merlin provides falsified records of Lancelot's noble birth and Lancelot is accepted. However, with the winged beast- discovered to be a Griffin- still on the loose, Merlin's decision could have far-reaching consequences not just for Lancelot but for Camelot...

When the Lady Morgana is struck down with a mysterious illness, Gaius is at a loss for a cure. Thankfully a new physician, Edwin Muirden is on hand to bring the King's ward back from the brink.

Morgana has a nightmare and sees Arthur's death at the hands of a strange but beautiful girl. Meanwhile, hunting in the forest, Merlin and Arthur save the same girl, Sophia, and her father, Aulfric from attack by bandits and bring them to Camelot for refuge. Morgana realizes that Sophia is the girl from her nightmare and tries to warn Arthur, who is smitten with her. As the truth of Morgana's magical gift for seeing future events unfolds, so does a father and daughter's plan to bring down the kingdom of Camelot by sacrificing Arthur in return for eternal life.

Merlin finds himself becoming friends with Morgana when he helps a boy stay hidden. The two of them try to get the boy back whence he came, but things turn bad when Uther announces that anyone helping the boy will be executed.

Uther's past comes back to haunt him as a mysterious Black Knight interrupts Arthur's coming-of-age celebrations, throwing down his gauntlet and challenging the Knights of Camelot to combat. The Black Knight, seemingly unstoppable, makes easy work of his combatants. But who is the Black Knight, and why is Uther so uneasy?