Gwen's father, Tom, agrees to help a renegade sorcerer, Tauren, turn lead into gold using a magical stone. Halfway through the act, a voice rings out - they're both under arrest. Several guards appear out of the shadows, led by Arthur. Tom goes quietly but Tauren uses magic to escape.
Morgana goes looking for Gwen. Amongst the debris of the chase in the forge, she finds the magical stone which the sorcerer must have dropped during his escape. Morgana places the stone in her pocket and heads off. Merlin can sense the stone but is unsure what the powerful feeling of magic means.
Morgana realises that Tom's trial is just a formality; Uther has made up his mind about Tom and will find him guilty no matter what. She therefore decides to take matters into her own hands. She steals the keys to Tom's cell, sneaks down into the dungeons and slips them to a stunned Tom.
Later that night, Tom makes a bid for freedom but, when the guards discover his cell is empty, Uther orders he be found and executed on sight. Despite his best attempts, Tom is caught and struck down. Gwen is devastated.
When Morgana hears the news, she charges to Uther and reprimands him for his behaviour. Frustrated with her attitude, and continued lack of respect, Uther has her thrown into prison, where she is shackled to the wall.
The following day, Arthur talks Uther into releasing Morgana. The King's ward is relieved to be free - but this is short lived when Gwen tells Morgana about a visit from Tauren, who demanded his stone. Morgana tells her not to worry about it. She will send the guard out to catch the sorcerer.
Once again, Merlin senses the stone. He sets out, following the high pitched whine, determined to discover its source. He is stunned to discover it is Morgana! He follows her to the woods, where she meets with Tauren.
Though initially wary, Tauren thanks Morgana for returning the stone. She asks what business they had with Tom - he got the poor man killed, leaving his daughter an orphan. He tells Morgana he wants Uther dead, but that he needed gold to fund his plan. Tom was helping him and would have been amply paid. Merlin is shocked as Morgana tells Tauren she will help him kill the King.
Unable to talk to Gaius for fear of exposing Morgana, Merlin heads off to seek council from the dragon. However, he does not like the advice the Dragon provides - he tells Merlin that when the King dies, magic can return to the land. Merlin tells him he cannot let an innocent man die. The dragon reminds him that Uther is far from innocent. His crimes fill the pages of history. If ever a man deserved his fate, it is Uther. Merlin is torn.
Morgana goes to Uther and tells him that she wants to visit her father's grave. She cleverly manipulates Uther, pulling at his heart strings...she wants them to put the bad memories to rest and help heal the rift between them. She knows that this is the one request Uther cannot refuse.
When Morgana slips out to meet Tauren again, Merlin follows. Morgana tells Tauren that the next morning she will leave Camelot with Uther and a minimal guard - giving Tauren the perfect opportunity to carry out the assassination.
The following Morning, Merlin watches anxiously as Uther rides out with Morgana. Merlin asks Gwen if she wants revenge on Uther - many people would wish him dead for what he did to her father. Would that make her feel better? Gwen replies that Uther's death is not what she seeks - that she is not a murderer. Merlin realises Gwen is right and rushes out of Camelot to save the King.
Morgana and Uther leave the guard and head up a bleak mountainside to the grave. At the graveside, Uther's emotions start to show - he tells Morgana that he feels he owes her so much. Over the years since her father's death she has been the one thing that kept him sane. We see that Uther's words are getting to Morgana - she apologises for her recent behaviour - or is she really apologising for her part in the imminent assassination?
Merlin approaches the site and finds the guards have been slaughtered, he sees the renegade sorcerers closing in on Morgana and Uther. Merlin pursues them up the hillside, using the Sidhe staff to pick them off one by one. However, when he fires at Tauren, the sorcerer uses the mage stone to repel the blast, turning it back on Merlin, knocking him out.
Tauren heads on up the hill towards Morgana and Uther. As Tauren prepares to strike, Morgana has a change of heart, Uther's words ringing in her ears. She alerts the king as to Tauren's presence and the pair tussle. Just as it looks like Uther's taken his last breath, Tauren's face falls. The pair look to see Morgana has run him through with Uther's sword. Merlin comes too just in time to see the pair united in an embrace and Tauren dead at their feet.
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.