Inside a dark cave, three hooded soothsayers chant and dip the tips of their staffs into the water of a pool before them. One kneels down to retrieve a coin from the water. A man named Osgar waits outside; the coin is given to him and he is told: "The fate of Arthur Pendragon lies in your hands now."Meanwhile, Mordred and Arthur are engaging in combat in Camelot's training grounds. Merlin looks on worriedly - and then a little grumpily when Arthur can't stop talking about how promising Mordred is as a young knight. Though he shares his concerns with Gaius, he's only told that the future isn't set in stone: they don't know for certain that Mordred will kill Arthur.During a council meeting, Sir Leon enters the room with some bad news. Whilst trying to apprehend a sorcerer called Osgar, one of Arthur's knights was killed. Despite Guinevere's attempts to convince Arthur to stay in Camelot and let his knights bring Osgar to justice, Arthur is determined to avenge his old friend. And as an added bonus - he's decided to take Mordred on his first mission! Mordred is delighted at the news, promising that he won't regret it.Naturally, the other knights can't resist ribbing Mordred a little as they prepare for their departure, whilst Merlin voices his doubts to Arthur concerning Mordred's youth and inexperience. From the front steps of the castle, Guinevere asks Merlin to look after Arthur, and the two friends share a resignated smile about how difficult Arthur makes it.Whilst riding through the forest, the knights partake in some more fazing of Mordred, having convinced him that all knights should ride backwards in the saddle in order to "meld" it. Having noticed signs of Osgar's passage, they all dismount and begin to follow him on foot, swords drawn. Having separated from the others, Elyan and Gwaine spot Osgar sitting on a log in the forest ahead, though he turns around quite calmly as they approach, telling them that he has an important message for Arthur. But Elyan and Gwaine are a little sword-happy today, and having stabbed him in the side, are flung through the air to be knocked out by a couple of trees. Osgar staggers away, holding his side.He reaches Merlin, Arthur and Mordred in another part of the forest and falls at Arthur's feet.
- Osgar: I am sent from the sacred Disir to pass judgment on Arthur Pendragon, the Once and Future King.Mordred: What right have you to pass judgment?Osgar: No man is above the Disir, however royal. It is my duty to pass their judgment onto you, dread king. My sacred duty...
- Mordred: Until then, we go unmarked in death as in life.
- The Disir: And now you come here, to the most sacred of the sacred, to the very heart of the Old Religion, with weapons drawn, trampling hallowed relics, treating our sacred space like you do our kingdom: with arrogance, with conceit, with insolence!
- Gaius: Only your magic can save him.Merlin: I cannot save the life of a man destined to kill Arthur.Gaius: If Mordred is destined to take the king's life, why has he just saved it?Merlin: I cannot ignore what the dragon said.Gaius: What happened to the young boy who came into my chambers just a few years ago?Merlin: He grew up. And he learnt the meaning of duty.
- Arthur: My heart says do whatever I have to do to save Mordred. But I've seen what misery unfettered sorcery brings. Before my father outlawed magic, Camelot was almost destroyed by sorcery. In my own time, Morgana's used it for nothing but evil. What would you do in my place?Merlin: Me? I'm just a lackey, a maker of beds.Arthur: Lackeys can be wise. It's not like you to be silent.Merlin: The kingdom's future is at stake.Arthur: And a man's life.Merlin: You must protect Camelot, you must protect the world you've spent building. A just and fair kingdom for all.Arthur: You'd have me sacrifice a friend.Merlin: I would have you become the king you're destined to be.Arthur: If I do save Mordred, all my father's work will be for nothing. Sorcery would reign once more in Camelot, is that what you'd want? Perhaps my father was wrong, perhaps the old ways aren't as evil as we thought. So what should we do? Accept magic or let Mordred die?
- Call Back: Guinevere mentions Arthur saving Mithian's father in the last episode.
- Designated Villain: Invoked with Mordred. Not only does he not do anything suspicius, but he seems to be a Hero-Worshipper toward Arthur and a borderline Knight Who Says Squee when assigned to his first patrol. The only reason to suspect him are the dragon's words.
- Downer Ending: At the end of the day magic is still outlaw thanks to Merlin; Arthur busted his last chance to change his (and possibly Mordred's) fate and Mordred is alive and well.
- Esoteric Happy Ending: In-Universe. As far as Arthur is concerned, his knight is alive and this proves the Old Religion is just superstition, while Merlin realizes Arthur has sealed his own doom.
- Expy: The Disir are highly reminiscent of the Three Fates of Greek Mythology or the Three Witches from Shakespeare's Macbeth. This makes sense in an episode based so heavily on the notions of destiny and the fate of kings.
- The disir are from Norse Mythology, female spirits in charge of fate.
- Grey and Gray Morality: The Disir blackmail Arthur into bringing the Old Religion back. Merlin is going to let Mordred die to save Arthur.
- Heroic Sacrifice: Osgar. At least he considers it as such.
- I Owe Him My Life: Arthur about Mordred.
- Idiot Ball: You know, whether or not you believe in a certain religion, going armed and wrecking their place of worship is an extremely stupid thing to do on what is essentially a diplomatic mission. Arthur acknowledges this later.
- In the Hood: The Disir
- It's All My Fault: Arthur blames himself for Mordred's injury. Later, Merlin blames himself for Mordred's recovery.
- Meaningful Echo: In 5x02 we had this:Arthur: What happened? As a child you were so kind, so compassionate.Morgana: I grew up.
Gaius: What happened to the young boy who came into my chambers just a few years ago?Merlin: He grew up.
- In this episode, we got this:
- It can also be read as an Ironic Echo.
- Nice Job Breaking It, Hero!: Merlin screwed up big time.
- Red Shirt: Sir Ranulph, whose death brings about Arthur's meeting with the Disir. Notable in that we don't even get to see him alive, yet apparently he's been friends with Arthur since they were kids.
- Rule of Three: The Disir
- Sadistic Choice: Prevent Arthur's prophesied death or have the ban against magic repealed. Then it turns out it's not really a choice in the first place.
- Self-Fulfilling Prophecy: Merlin fell into this trap. Again.
- Shoot the Shaggy Dog: Merlin spends the episode warring between saving his friend and bringing magic back to Camelot. He's finally forced to make a decision and chooses Arthur, possibly removing his one chance to bring magic back to Camelot... and it turns out that all he did was restore Mordred to full health.
- Stepford Smiler: Finally averted with Merlin. Lampshaded by Arthur who points out that he hasn't smiled in three days.
- Taking the Bullet: Mordred to Arthur.
- Wham Episode
- What the Hell, Hero?: Gaius to Merlin, when he choose to let Mordred die while not knowing for sure if he will kill Arthur.
- Wound That Will Not Heal: Mordred gets one from the Disir.
- Unexplained Recovery: Mordred. Presumably the Disir did something, but it's never given any real explanation.
- You Can't Fight Fate