Glimmer (слэш)

The other nobles didn't have to tolerate pointed comments about their intelligence or the size of their waistline (which had not changed an inch, no matter what Merlin said.) They did not have to suffer messy chambers and the frustration of a manservant who would not do what he was told unless it suited him.
And perhaps Arthur was petty, but it did give him some small satisfaction to see Merlin scowling at him from the edge of the duelling ring.
'He'll turn you into a frog,' Gwaine said cheerfully, swearing as Arthur dodged the blow of his sword and smacked Gwaine's exposed side with the flat of his own weapon. 'Chuck you in a well and leave you there.'
Arthur discovers there's a difference between knowing Merlin has magic, and truly seeing it for himself.