Sorry for my English, I am not a native speaker
Merlin is starting to show Arthur abilities beyond being loyal and funny (and occasionally wise). In the first place, he promises Arthur that they will save Gwen. How can a skinny servant make such a promise? Is he more powerful than a group of warriors? In the second place, Arthur was completely amazed by the fact that Merlin knew the way through the forest. Moreover, he did not buy his servant's excuse. I liked that very much.
Morgana brainwashes Gwen using mandrake roots. Maybe Morgouse brainwashed Morgana the same way. I really hope so. In that case, is the process reversible? Morgana is one of my favorite characters and it would make me happy if she found redemption in the end.
I loved Morgana's weird mixture of evil and tenderness. When Gwen almost succumbs in the tower I was thinking "Come on, come on!" and in the final scene I was like "Yes!!!". Morgana hugging Gwen made my day. Other great moments:
Sir Leon's scream almost gave me a heart attack.
Sir Gawain dreaming "a cheese that tasted of apple pie". Merlin and Sir Leon looking at him when he asks if someone else had the same dream.
Arthur rubbing his eyes and laying his head on his hand when they stop to sleep after having realized that they have wasted an entire day going in circles.
Arthur and Gwen spooning.