[ Morgana finds Merlin later, after Arthur - a significant time after, actually. She's been thinking, trying to collect her words. What she saw didn't make sense at first. It still doesn't quite make sense now. For all she knows Arthur to complain the loudest about those of whom he is most fond, this is a step she never saw coming.
Perhaps she should ask Arthur about it first. But somehow this seems easier.
She doesn't mean to sneak up on him, doesn't notice how ghostly quiet her steps are as she approaches from behind. ]