High in the mountains, a great horde gathers; Morgana prepares for war with a vengeful Mordred at her side. Merlin feels the weight of his destiny like never before as the ancient prophecies play out with terrifying accuracy. But before he can save his beloved Camelot, he must save himself. For it is not just the kingdom Morgana wishes to destroy – it is also Emrys.

And so it seems the Prophets did not lie. As the great battle rages on Camlann's mighty plain, Merlin faces his moment of destiny. Can he find the strength to save the man he made a King; the Camelot they fought to build; and the brotherhood they shared?

Morgana is now the head of a vast Southron army and a deadly net is closing around Camelot. After the sorceress strikes everyone is forced to run for their lives including Arthur. It is down to Merlin to try and save Arthur from Morgana's clutches.

The kingdom is on the brink of collapse and Morgana poised to strike, in the final part of this opening episode of the fantasy drama. As Lancelot races back to Camelot with the dying Merlin, Arthur must continue on his mission to vanquish the Dorocha without them. Though the Knights know their journey to the Isle of the Blessed is fraught with danger, none could anticipate the sacrifice Arthur intends to make there. Friendship and loyalty are tested to the limit, but in the end, it's the power of love that changes all their lives for ever.

Evil sorceress Morgana summons mighty gatekeeper the Cailleach, who opens a door to another world from which hellish creatures pour forth. As Arthur and his loyal knights take up arms, Merlin discovers the only thing that will stop them is an unimaginable sacrifice.

Merlin becomes a deadly weapon in Morgana's fight for supremacy when he falls into her hands. By recurring to ancient magic, she manages to turn friend against friend and creates the perfect assassin out of the young sorcerer which puts an oblivious King Arthur in great danger. Will anyone notice Merlin's unusual behaviour before he is able to do any serious harm to the King?

Mordred finds himself torn between loyalty and love, but little does he realise that the path he chooses will shape Camelot's destiny. As the drums of war beat ever louder, a desperate Merlin feels trapped by the cruel circle of fate - is he powerless to stop his dreams of Albion from crumbling to dust?

A mysterious visitor arrives in Camelot seeking a very special prize: a dragon's egg.

The mighty citadel is buzzing in anticipation of the Prince's birthday celebrations, as the fantasy drama continues. But Arthur's old adversary, Odin, promises to ensure this is one party Camelot will never forget - for among the assembling guests lurks a deadly assassin set to strike. As the dust settles, Camelot is left devastated. Just how far is Merlin prepared to go to put things right; would he really risk everything and reveal his secret?

As dawn breaks across the icy tundra, Merlin and Arthur are close to exhaustion. With each tortured step, the fortress of Ismere looms ever nearer and Merlin's fear intensifies. What game is Mordred playing? And what powerful secrets are Morgana and the druid Ruadan (Liam Cunningham) searching for amongst its twisted catacombs? It seems like this time, not even Merlin can stop Arthur from walking right into the lion's den… For in this bleak and transient wilderness, only one thing is certain: the great trial for Albion has finally begun.

On a hunting trip, Arthur comes face to face with a creature of great power from the old religion. When Gaius informs them that it can only be killed by magic, Uther refuses to listen and sends out his knights to kill it. Arthur is fatally wounded and Merlin must go to the Isle of the Blessed to save him. But will he be able to pay the price?

Freya is found by Merlin trapped in a bounty hunter's cage and decides to try and help her escape. Merlin refuses to listen to Gaius' warnings not to get involved. After freeing her Merlin hides Freya in the tunnels beneath Camelot. Merlin is forced to make some hard decisions to keep Freya safe.

Arthur and Merlin embark on a dangerous mission to capture the Cup of Life, a powerful magical artifact that carries the gift of immortality. However, before they are able to retrieve the Cup they fall prey to Jarl, an unscrupulous slave trader. They manage to escape when a trusted friend comes to their rescue but with Jarl's help, the Cup of Life ends up in Morgause's hands. Now that the dreadful sisters count on an immortal army at their disposal, will Morgause and Morgana overthrow Uther once and for all?

Arthur brings a curse upon Camelot. Eager to help his people, he asks Anhora for advice. But is he brave enough to face the challenges ahead?

Merlin knows he must act fast before Morgana’s twisted control over Gwen gets further out of hand. But only the most powerful magic can save the Queen and this will not be easy, even for Merlin. As the High Priestess tightens her grip on Camelot, one thing is clear - she will not give up her puppet without a fight.

Arthur is challenged to a duel by a mysterious warrior. Arthur and Merlin then find themselves on a quest on Morgause's behalf. A dark secret is discovered by Arthur that could change Camelot forever.

Camelot's legendary tournament only has one rule: there are no rules whatsoever. Terrifying warriors start to fill the mythical city, Gilli between them. Despite his small stature, Gilli is ready to join the action and committed to achieve victory with a secret weapon to help him: magic. When Gilli begins to realise the full extent of his powers, Merlin becomes torn since his new friend is putting his own life in danger as well as threatening the very heart of Camelot with his actions. Will Merlin be able to make Gilli see sense before it's too late?

Lady Catrina has now been crowned and is now known as Queen Catrina. She accuses Merlin of stealing and he is driven into hiding, and must now find a way to expose her true form.

A mysterious illness draws Merlin to a distant village. But it soon becomes clear that there is more at stake than just his patients' well-being as something sinister turns the air sour. Far from home and with no-one to trust, Merlin becomes embroiled in a deadly game of cat and mouse. No longer sure who is the hunter and who is the hunted, can the young warlock survive long enough to uncover the truth?

When Gwen is snatched from Camelot without warning, Merlin knows there can be only one person responsible: Morgana. Arthur is determined to rescue his Queen – but it's not going to be easy, for she is locked in the Dark Tower, a place that haunts the dreams of men. Arthur and his Knights must embark on a quest like no other, battling through a landscape riddled with hidden dangers, perilous obstacles and magical beings. As they near their goal, Merlin's sense of dread reaches breaking point. What twisted game is Morgana playing? And more importantly, just what is the final test that awaits them in the tower?

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.

Uther pressures Arthur into an arranged marriage with a visiting princess, Elena, though Merlin soon has reservations after discovering that Elena may not exactly be who she claims to be. As he tries to uncover the princess' dark secret, he learns that Elena's nanny is a Pixie. But what are their motivations? Who do they work for? And most important of all, what benefit do they get from her marriage to Arthur, the heir to the throne of Camelot? Will Merlin be able to get to the bottom of it all and prevent Arthur from making the biggest mistake of his life?

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.

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.

Peace talks are held at Camelot when dignitaries from rival kingdoms arrive. King Alined is determined there will be no peace though and will use magic to make sure his wishes happen.

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.

When a stranger gives Arthur the power to summon the dead, the king finds himself torn between head and heart. Unable to resist temptation, he seizes the chance to speak to the person he misses most – his father, Uther Pendragon. But the spirit world is a dark and dangerous place, for little does Arthur realize that his decision comes at a terrible price. Against all odds, Merlin must put right Arthur's mistake before Camelot, and everything they have built, is destroyed forever.

When Merlin agrees to help a young Druid boy, he has no choice but to leave Camelot on a dangerous mission. And with the citadel distracted by the visit of the fearsome Sarrum of Amata, it seems that no one will notice his absence. But as the sky darkens, so do Merlin's suspicions - is there more to Daegal than meets the eye? And can a man as ruthless as the Sarrum ever really be trusted? Too late, the young warlock realises he's made a terrible mistake.

Gwen is mistaken for Morgana and kidnapped by the savage outlaw Hengist. Uther refuses to pay her ransom, so Arthur defies his father and heads out into dangerous enemy territory to fight for Gwen's freedom. Merlin suspects Arthur's devotion to Gwen is more than that of a prince to one of his subjects. How will Arthur react when he discovers Gwen is not alone in Hengist's castle? She and Lancelot have found each other again, and powerful feelings rekindle.

When Morgana's nightmares spill into waking hours, she becomes terrified that she has the power of magic. Gaius is determined to keep her in the dark for her own good but Merlin won't stand by and watch his friend suffer. He knows exactly what she's going through and he knows she needs the truth. Is Merlin about to reveal his secret at last?

When Sir Lancelot returns from the dead, old feelings reignite, as the drama continues. Gwen must fight temptation before she commits an unspeakable act of betrayal; one that would destroy the legacy of Camelot forever. With heads and hearts thrown into turmoil, Merlin becomes suspicious. Can a man really defy death, or is there something more sinister at play?