Will Arthur be able to save Camelot from the evil Morgana? Morgana, newly crowned as Queen of Camelot, begins a reign of terrible evil over the innocent citizens of the kingdom. Counting on Morgause and her immortal army at her command all hope seems lost for Uther, who is forced to witness how his kingdom crumble under the unimaginable cruelty of his own daughter. Meanwhile, on the outskirts of Camelot, Arthur recovers his strength and plans a counter attack with the help of a few loyals at his side: Gwaine, Lancelot, Elyan and Percival. However, Merlin is aware that not even a skilful warrior like Arthur can defeat an immortal foe without magic. Will he be able to reclaim the great sword Excalibur from the Lake of Avalon in time to save the lives of those he cares the most about?

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.

Morgana and Helios have successfully captured Camelot, and Merlin and Arthur are outlaws on the run, in the last episode in this season of Merlin. Trapped in Ealdor with a ruthless army closing in, their situation becomes desperate. Arthur must take control before Camelot is lost forever… But faced with Agravaine’s betrayal and the strength of Morgana’s force, the young King has lost his conviction. Only Merlin can restore his faith, and only an extraordinary act can prove to the King that he was born to rule. Will the young warlock convince Arthur before his dreams of Albion fall to pieces?

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 embarks alone on a quest to prove himself worthy of the Camelot throne by retrieving the Golden Trident from the Fisher King. With the Prince beyond the protection of the citadel, Morgana takes the opportunity to use her dark magic. She gives him a precious bracelet that contains a Phoenix Eye, insisting that he wears it at all times for protection. However, the magical jewel takes away Arthur's life force and he is left defenceless in the Fisher King's perilous realm. With the help of Gwaine, will Merlin be able to reach Arthur in time and fulfil his own quest to protect the future king of Camelot?

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?

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 Great Dragon is finally free. Full of rage, he attacks Camelot with pitiless intensity. The castle is crumbling and Arthur's men cannot hold out much longer but only a Dragonlord can kill a dragon and Uther wiped them all out years ago. Or did he? Gaius admits one such man could still be alive and in hiding. The last Dragonlord is the key to Merlin's own past as well as the future of Camelot, but will Arthur and Merlin find Balinor in time to save the kingdom?

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?

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?

When Uther banishes Gwen from the kingdom, Arthur resolves to leave Camelot with her.

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?

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?

A year after her disappearance and when almost all hope is lost, Morgana returns to Camelot. While Merlin is afraid she might remember the circumstances of her disappearance and give him away in front of the king, a delighted Uther announces a banquet to celebrate. However, soon afterwards evil magic starts to take hold of the king's mind, putting the safety of Camelot at risk as he is consumed with hallucinations and enemies reach his door. Merlin suspects Morgana is behind the enchantment but his search for the truth puts his life in peril while Arthur is forced to take control and face new foes on his own. Will they succeed to rescue the king and Camelot from destruction?

With the help of the Great Dragon, Merlin manages to return to Camelot only to find out that is it on the verge of invasion: Morgause and Cenred have teamed up and plot against a weakened Uther. Cenred's initial reluctance is won over by the fact that they count on an ally within Camelot walls who will ensure the castle is taken. Uther is unable to rule which forces Arthur to step up front and defend the citadel agains Cenred's powerful army. With the help of Morgause and to make things worse, Morgana plays a deadly card and summons a skeleton army to wreak havoc within the castle walls. Camelot's fate rests once again on Arthur's shoulders and Merlin's magic as they fight in their own way to hold off both an army of the living and an army of the dead. Will they manage to succeed?

Morgana joins forces with enigmatic wizard Alator to uncover a secret that could change the course of destiny, as the magical drama continues. With allies on both sides of the castle walls, can anyone stop her before Merlin's greatest secret is revealed?

Merlin is stunned when his mother, Hunith, turns up in Camelot--bruised, battered and desperate for help from Uther. She explains to Uther that a bandit named Kanen and his men have been attacking her village demanding all of their harvest or he will kill them. When Uther refuses to help, Merlin leaves Camelot to protect his mother and friends. To Merlin's surprise, Arthur, Morgana and Gwen join forces with him to save his village--but at what cost?

Merlin and Arthur find themselves outnumbered in a bar fight but an enigmatic young man helps them win. The man’s name is Gwaine and he risks his own life to protect Arthur but during his act of bravery he is seriously wounded. The Prince decides to take him back to Camelot where he could make a recovery with Gaius' help. Gwaine immediately gets to work: drinking, flirting with the ladies and causing lots of trouble for Merlin who has been instructed to look after him. However, when two unscrupulous knights seem to plot to murder the Prince, will Merlin and Gwaine be able to stop them and save Arthur?

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

Arthur faces his first true test as King when he incurs the wrath of the formidable Queen Annis. With the lives of thousands hanging in the balance, Arthur must find the strength to be his own man and become the leader Camelot so desperately needs.

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.

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.

After an unexpected meeting with the enigmatic old sorcerer Taliesin, the wizard takes Merlin to the crystal cave allowing him to witness a glimpse of the future. However, this gesture turns out to be more of a curse than a gift when, much to his horror, Merlin sees Morgana set to kill Uther. The young warlock knows he must do his best to try and stop the future from playing out. But changing the pages of destiny is a very dangerous game and his actions end up having fatal consequences. With the whole of Camelot in a state of grief, will Merlin be able to change the course of destiny and undo the damage he has caused, or will it be too late?

Morgana ends up discovering a powerful ally in the Southron warlord Helios and they come up with the perfect plan to bring Camelot to its knees. With Arthur preoccupied by the beautiful Princess Mithian, it ends up falling to an absent friend to raise the alarm.