Michelle Ryan

As Bayard and the Knights of the Western Isles are welcomed to Camelot for a feast, Nimueh infiltrates Bayard's entourage and begins a plot to get revenge on Merlin. Posing as a servant girl, Nimueh tricks Merlin into drinking from a poisoned chalice. Falling gravely ill, the only chance Merlin has is for an antidote to be prepared. Arthur takes it upon himself to retrieve the needed ingredients but, with Nimueh doing everything she can to thwart Arthur's quest, will they be able to save Merlin in time? Bayard and the knights of the Western Isles are welcomed to Camelot for a feast celebrating a union between the two kingdoms. Nimueh, however, has other plans. Posing as a serving girl, she infiltrates Bayard's party and enters Camelot with a view to seeking revenge on Merlin. Unaware of her true identity, Merlin befriends the young serving girl. Once she has gained his trust, Nimueh warns him that Bayard isn't the friend he seems as he plans to poison Arthur. Merlin bursts into the banquet and stops Arthur drinking from a poisonous goblet in the nick of time. Bayard denies trying to poison Arthur and Uther decides that the only way to determine the truth is for Merlin to drink from the cup himself. Merlin falls to the ground, poisoned. The guards arrest Bayard and his knights. Merlin falls into a deep coma. Gaius discovers that Merlin has been poisoned by the Morteaus Flower and can only be saved from certain death by an antidote made from the leaf of the same plant. However, the flower is rare and only grows in the caves of Mount Argeaus, which are found deep within the forest of Balor. As Merlin's health deteriorates fast, Arthur, humbled by his servant's bravery, believes he must set off on a quest to retrieve the flower himself. But Uther forbids him to go because the danger is too great. Morgana counsels Arthur and helps him realise that he is his own man and should do what he thinks is right, even if it means disobeying Uther. Will Arthur find the flower in time to save his friend or will Nimueh place more danger in his path?

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.

A mysterious knight arrives in Camelot, uncovering a secret from the past that Uther would prefer stayed buried. At Arthur's coming-of-age ceremony, the celebrations are interrupted when a mysterious Black Knight crashes his horse through the window. He throws down his gauntlet and challenges the knights of Camelot to single combat. Sir Owain, a young, eager knight, picks it up and accepts the challenge – they will fight the next day. Uther is as white as a sheet as he watches the knight go, staring intently at the distinctive crest which marks his helmet. The following day, a large and nervous crowd gathers to watch the fight. Sir Owain strides out to the waiting Black Knight and the pair do battle. The Black Knight is an awesome warrior, and it looks like Sir Owain doesn't stand a chance. However, Merlin is delighted when the young knight successfully strikes his opponent. He sees the blade go in but the Black Knight doesn't even flinch and, seemingly unaffected by the blow, he goes on to slay Sir Owain. Later, Gaius takes Merlin down into the crypt below Camelot and to the tomb of Tristan De Bois. Gaius is horrified to see that it is empty – his body has gone. Merlin listens as Gaius explains that the mysterious knight bears the crest of Tristan De Bois, who was the brother of Uther's wife. Driven mad with grief, he blamed Uther for his sister's death in childbirth. Gaius tells Merlin that he thinks the Black Knight is Tristan De Bois, brought back from the dead to exact his revenge. Merlin discovers that there is only one way to kill a vengeance wraith – with a sword forged in a dragon's breath. But is it too late for Arthur who, determined not to lose any more of his knights, is due to fight the Black Knight the following day?

When a London bus takes a detour to an alien world, the Doctor joins forces with the extraordinary Lady Christina. But the mysterious planet holds terrifying secrets hidden in the sand. And time is running out, as the deadly Swarm gets closer.

Whilst out on a routine hunting trip, Arthur and his men encounter a huge and terrifying monster. It has the body of a lion and the head of a serpent, with a huge pair of dripping fangs. Gaius explains that what they encountered was a Questing Beast, said to have been conjured from the nightmares of a long-dead King. It is a creature of great power from the Old Religion, whose bite is always fatal. Uther refuses to acknowledge such folly and sends the Knights out to kill it. Arthur and his men creep through the forest and find the tracks of the beast. As they cautiously enter its lair the beast jumps out of the darkness at Arthur. Merlin uses magic to send a sword flying at the creature, and it vaporises before his eyes. The beast is dead, but Arthur lies unconscious on the floor, blood dripping from his shoulder – he has been bitten. Arthur is rushed to Gaius – the physician takes one look at the ailing prince says there is nothing he can do, the teeth of the beast have done their evil work. Arthur will soon die. Merlin blames himself for failing in his destiny to protect the Prince. He tries to use magic to save Arthur but it doesn’t work. Gaius tells him that the bite of the Questing Beast is a death sentence which no magic can overturn. The castle goes into mourning, but Merlin refuses to give up, he seeks the help of the Great Dragon who tells him that all is not lost. The Dragon tells him he must go to the Isle of the Blessed and ask the old religion to save Arthur – it alone has the power. Merlin goes back to Gaius with the clues the dragon has given him. Gaius fills in the gaps – the ancient magic which has the power to mirror life can reverse death itself, but there will be a price to pay. Merlin journeys to the Isle of the Blessed where he finds Nimueh waiting for him. Nimueh tells Merlin that she can save Arthur’s life but he must know that a price will have to be paid. To save a life, a life must be taken. A desperate Merlin says that he will take that chance, Arthur’s life is worth anything. If he has to give up his own, then so be it. Nimueh shows him a gold chalice – it is the Cup of Life, blessed by centuries of powerful sorcery so that it contains the very secret of life itself. She tells him that if Arthur drinks water from the cup, he will recover. She gives Merlin some water to take back to Camelot with him. Merlin feeds Arthur the water from the chalice - he slowly shows signs of recovery. Gaius declares he will live. The castle rejoices that their Prince is recovered – and Merlin awaits his fate - but when his mother, Hunith, arrives and is gravely ill, Merlin is distraught. His mother is ill because of the bargain he struck. Merlin already knows what he must do. He tells Gaius if the balance of the world needs a life, it must take his. He will return to the island and give his life in Hunith’s place. An anguished Gaius tries to dissuade him – Merlin’s talents, his destiny, are too precious to be sacrificed but Merlin refuses to listen, he has no choice – he cannot let his mother die. Returning home to collect his things, Merlin finds a letter. It tells him that Gaius has gone to the Isle of the Blessed in his place. Gaius lovingly acknowledges that Merlin’s life is worth more than his and it is his that should be given instead. Merlin thunders after him - will he be able to catch him before it's too late?