This follows the plot of chapter 31
Merlin was surprised to see Nimueh when he got to his room.
"What are you doing here?" he demanded.
Nimueh smiled in a way that was supposed to be reassuring but ended up being creepy. "I know about you teaching magic Merlin," she said deciding to get straight to the point.
"How?" He had only had one lesson so far. How could she have possibly found out so quickly?
"How I know isn't important. What is important is that you don't really have much to teach, but I can change that."
"Why should I trust you?"
"I want magic back in Camelot as much as you do Merlin."
"I don't exactly approve of your methods and I don't need you to teach me anything."
"If you ever change your mind you know where to find me," she said before vanishing.