Personal responsibility is the watchword for this episode...well that and bitch...because Morgana is a major one of those.
When Sir Lancelot returns from the dead, old feelings reignite. Gwen must fight temptation before she commits an unspeakable act of betrayal, one that would destroy the legacy of Camelot forever. With heads and hearts thrown into turmoil, Merlin becomes suspicious. Can a man really defy death, or is there something more sinister at play?
Arthur makes a bold decision - he's going to ask Guinevere to marry him. Agravaine takes this information to Morgana who, enraged, vows to destroy the union by unleashing the one thing that can come between the noble lovers: Lancelot. With her magic, she brings the knight back from the dead, but as a shade who must bend to her will.
Back in Camelot, Arthur's successful proposal is celebrated with a tourney, but the event is interrupted by Lancelot's appearance. Everyone is thrilled, but Merlin quickly grows suspicious when the returned knight appears to not know about the young wizard's magical powers.
When Gwen does not immediately fall to Lancelot's charms, Morgana enacts her backup plan: An enchanted bracelet that fires Gwen's passions and leads to her into Lancelot's arms. A furious Arthur banishes her from Camelot despite her protestations and Merlin's attempts to beg Arthur to forgive her.
Soon afterward, Lancelot is found in his cell, apparently having committed suicide. Merlin takes the body to the shore of Nemhain, using his magic to bring peace to his deceased friend and setting his remains on their final journey across the lake.The Skinny:
Morgana's treachery knows no bounds...it's hard to believe this is the same girl that we met in first season who seemed so sweet to Gwen. I feel for Gwen...but Morgana's magic didn't create the problem that led to her exile from Camelot. The shade of Lancelot didn't create the problem either, though without him, her betrayal would have been impossible. No, the problem this time is that Gwen allowed herself to be overrun by her (magically enhanced) feelings and gave in to temptation. Even if, as I suspect, that magic was akin to Harry Potter's love potion (a spell of obsession), the afflicted still bears the responsibility for her actions. Arthur is quite right here...now that he's aware of her latent feelings for Lancelot, he can't (at least not now) truly trust her to be faithful to him alone. She needs to face the consequences of her actions before this can be made right.
On the merits, this episode is a little on the slow side and, considering Gwen's unfortunate departure and the effect Lancelot's real death had on Merlin, it should have been a little more powerful than it was. But I do like that personal responsibility is still valued in this canon universe, and I do like that Arthur is learning to govern differently than his father. Other than that...I don't have a ton to say about it, I'm afraid.
The plot drags a bit in places, and the audience knows too much yet again about Morgana's plans and so their attempts to drum up suspense for the jousting match don't work (we know that Lancelot isn't after Arthur). These writers seem to be doing a whole lot of telling, rather than letting things be revealed in time. We shouldn't have known anything about Lancelot except that he was up to no good and we should have figured out what was going on with Gwen as Merlin figured it out (or after Gwen leaves in exile, regarding the bracelet, which Merlin still doesn't know about).
That said, Colin Morgan, Katie McGrath and Angel Coulby were all well above their normal levels of expertise in this episode, I must say.
And I never fault an episode for having real consequences for bad behavior, even if that bad behavior carries some mitigating circumstances around it.