Gwen and Elyan are out paying their respects to their father, who you may remember Uther killed way back in season one (looking the wrong way at a sorcerer crossing the street, or something).
On the way back to Camelot, a hooded figure peeks from the trees… it’s MORGANA! And she’s got MAGIC SNAKES!
There are bites for Leon and Percival, and then she magically pulls Gwen off her horse, and steals her away.
The knights make it back to Camelot, assuming Gwen did likewise, but of course she’s missing, and Gaius and Merlin set about trying to heal the snakebites, which look pretty magical. They suspect Morgana right away, and Arthur pledges to ride out first thing to find Gwen.
The knights discover Gwen’s horse, and a trail heading east and set off to follow. Meanwhile, at the other end of the trail we find an exhausted Gwen, being led, on foot, across scorching ground to a spiky tower. She’s refusing water, which only makes Morgana more, y’know, Morgana-y: issuing dark threats and smiling, that kind of thing.
Morgana locks Gwen in the tower. It is dark. It’s a dark tower. But it is not a quiet tower, what with the human screams and everything. Gwen settles for an restless night’s sleep, even though she’s worn out.
Leon and Percival have had an identical nightmare about the tower – the Dark Tower. Arthur explains that it’s a legendary place of doom for knights, and Merlin reasons that if this is the case, they’re on their way into a trap.
Gwen wakes the next morning with mandrake root oil dripping on her face. That’s where all the screams have been coming from. The question is, how long can Gwen stay sane under such a mental barrage? Ah, oh dear, she’s started seeing visions. First a sneering Elyan, then a snarling Merlin. Arthur must hurry, if he wasn’t already, but the knights have their own problems – the Impenetrable (and Confusing) Forest.
While Arthur circles the tower, Morgana is playing nice. She offers Gwen dinner and some respite from the mandrake madness, but Gwen’s resolve is firm, for now.
As the knights make camp, and sleep, Merlin is visited by a spirit called Mab, who claims to be queen of the things men fear in their hearts (like TAXES! Whooo!). Mab’s riddles imply that they need to work against their own best instincts in order to get anyway, and that one of their party will not make it back to Camelot. And then she giggles, unhelpfully.
Next day, Merlin secretly uses magic to help the knights find their way. It does not endear him to Arthur at first, but they soon start making progress, and even break out of the forest.
Morgana’s kindness is sapping at Gwen’s resolve, as the hallucinations (Arthur this time, and some more snarly Merlin) and screaming continue.
The knights arrive at the tower. Inside it’s dark, a Dark Tower, and there are human bones on the floor. Elyan runs on ahead, and they find themselves in a throneroom with rigged flagstones that shoot arrows at the people standing on them. As the rest of the knights work their way across the room safely, Elyan goes ahead to find Gwen. Except she’s guarded by a magic flying sword that will only fight to the death. This cannot end well.
He takes up the challenge, seeing off the sword by trapping it behind a door, but not before he has been administered a mortal blow. He dies in Gwen’s arms, just as Arthur and the knights finally enter the room to take Gwen home.
Then it’s Elyan’s funeral, and apart from the upset and everything, all seems to be back to normal. Except you’re probably wondering what happened to Morgana in all this?
Oh great, she’s in the forest outside Camelot, waiting for a newly traitorous Gwen to meet her and discuss their plans to bring about Arthur’s downfall. All that mandrake madness and dinner kindness has paid off, she’s brainwashed Gwen into being a baddy!
This cannot end well either…