King Uther sends Arthur to find the Lady Morgana. Accompanied by Merlin, he searches the land, finding a wake of dead knights. Bandits attack and, when all is calm, a mysterious, bruised, bloodied, and filthy figure comes forward...it is the Lady Morgana.
Morgana returns to Camelot and everyone is eager to hear her story. It is not long until Merlin is summoned to her chambers. He panics when Morgana tells him she knows he tried to poison her, but she stops him and says she understands why he did it. Merlin is reassured to learn that her days of listening to Morgause are over.
Morgana visits Uther, and they embrace. Morgana takes a handkerchief from her robes and dabs his eyes. Later, under the cover of darkness, she travels to a secret cave guarded by warriors who bear the crest of the Bloodguard. Inside the cave, a solitary figure awaits...it is Morgause. The sisters embrace. Morgana confirms that everything is going according to plan and gives Morgause the handkerchief stained with the tears of Uther Pendragon. Morgause tosses it into the cauldron along with mandrake root, which pierces the deep recesses of the soul in those without magic, bringing madness in its wake.
The banquet is in full merriment. Uther excuses himself and goes outside for some air. He hears a scratching noise, which seems to be coming from the well. As he investigates, a woman's hand reaches out and clamps round his wrist. A face appears in the well. It is his dead wife, Ygraine. Uther screams. Guards come running to find Uther alone, slumped down, a sobbing wreck.
Morgana meets with Morgause, informing her all is going better than they hoped. Morgause tells her that she will visit Uther's enemy, Cenred, and convince him to attack Camelot. On Morgana's return, a guard stops her, and finds the mandrake root. Morgana has no choice and drives a dagger into his chest. The guard falls backwards off the drawbridge... into darkness.
Sir Leon informs the King of Cenred's growing army and wonders if they should send a patrol to assess the situation, but Uther offers up no response. He is hallucinating again. Meanwhile, Gaius tells Arthur and the other members of court that he found a guard stabbed with a dagger that bore the sigil of the Bloodguard, an ancient order of warrior priests sworn to protect the High Priestess of the old religion. To Morgana's horror, she learns that the guard is still alive and Gaius expects him to make a full recovery.
Morgana knows she has to do something and pays a visit to Gaius' chambers. She takes down a bottle of poison and stops for a moment; is she really going to kill this guard in cold blood? Merlin and Gaius return...to find a dead guard.
Whilst straightening Uther's sheets, Merlin hears someone enters the room, instinctively hides under the bed and sees the mandrake root. A hand reaches down and removes it. Merlin chances a look and, to his amazement, sees Morgana leave the chambers. Desperate to see the good in her, Merlin decides to find out whose side Morgana is really on.
He can hardly believe his eyes as he watches Morgana greet Morgause in a wooded clearing. Morgana says that everything is going well, except Merlin has cottoned on to the plan. Morgause insists they stop him. Morgana agrees and, knowing Merlin was there all along, she looks right at him. Time has run out for the young warlock.
Merlin awakes to find himself bound in chains. He mutters a few incantations, but cannot break free. He hears rustling in the undergrowth and realises he is not alone. As scores of giant scorpion-like creatures emerge, Merlin unleashes a raft of spells, but they only buy him a temporary reprieve. A giant poisonous tail scythes through the air, striking Merlin's arm, and he erupts in a magical rage. His vision weakens as the poison flows through his veins. In utter desperation, he calls out a strange guttural language we have heard once before.
A shadow looms in the sky high up above him...it is The Great Dragon, who swoops down, unleashing fire on the insects. Those that do not burn flee for the lives. The Great Dragon sets down beside Merlin. With delicacy, he scoops the warlock onto his back and with a gigantic beat of his wings, he soars up into the night sky.
Morgana and Mordred prepare to destroy Camelot (and Morgana plots to destroy Emrys). Is Merlin Camelot€™s last hope?
Merlin star Colin Morgan talks about the important events from episode 511 'The Drawing of the Dark.'
Mordred battles between his duty to his friends and that to his love, but is spared the choice.