A Hunting Trip

Note

"Sire, are we going to send out a search party?" Leon had walked in without Arthur even realising. He thought about this, there was almost no hope in succeeding, but they had to try!
"Yes, inform all the knights, we'll need as many eyes out as possible!" Leon rushed off, leaving Gaius and Arthur alone.
"Arthur, there's something I think you need to see before you head out..."
"What?"
"Well, I found this on Merlin's bedside this morning, probably left it before he did," Gaius explains whilst passing the paper over. Arthur took it lightly in his trembling hands, and he instantly recognised that this was Merlin's handwriting. It read only four words:

You can't stop us.

"What do you think he means, Gaius?"
"I honestly have no idea, but that's the only lead we have..." Gaius trailed off when he saw the note in Arthur's hand change. The words moved around, leaving another message.
"What was that?!"
"It must be enchanted, Merlin probably put a spell on before he left. What does it say?

Well done, Gaius, you're catching on! It's a shame you'll only have that skill for one day...

Both Arthur and Gaius stared at the note, shocked at what it said. They were left none the wiser about Merlin's whereabouts. Suddenly, Arthur spoke up.
"If the note is enchanted, it'll change whenever we say something, won't it?"
"That's how it should work, why?"
"What if one note becomes two? Will they say the same thing?"
"I'm not sure... do you think the enchantment could tell us?"
"I don't know, you're the one who has all the magic know..." They stop talking when they notice the letters moving around yet again.

You two are complete idiots! If you destroy the note, the enchantment breaks with it! Sorry to burst your bubble... your plan won't ever match ours!

"Who? Where are you?"

Can't tell you that! Sneaky Arthur, but even the biggest search party won't find us!

"Who are you with? What've they done to you... this isn't you, Merlin!"

Oh, Gaius, this is me, except I'm more knowledgeable now. I know how it feels, I can relate to her, and she's helping me... not like you ever did!

Gaius stared at the words, and they didn't move. It was purposeful, to let it sink in. Arthur looked at the broken physician, he must feel awful. If what Merlin says is true, he'd probably been executed his first day in Camelot! He knew Gaius would've helped Merlin, just not enough in his eyes.
"There must be more, you've been here for years, and now you leave... why, Merlin?"

Because I've found someone who knows what it's like to hide yourself, to be rejected by her friends, to have to pretend your whole life. She gave me light in the dark, and that darkness was because of the one holding this paper! Turns out you are EXACTLY like your father, Arthur Pendragon, and she and I have a plan for your tyranny to end!

Arthur gives a worried look to Gaius, they both know who Merlin's referring to. Morgana.