Perhaps We Could Grow Beyond
After Arthur is rescued from Sophia, he speaks up against Uther and convinces him that Merlin only lied to him because Arthur ordered him to, therefore rescuing him from another day in the stocks. After that in his chambers he hugs Merlin and thanks him for saving his life. Merlin says that he should also thank Morgana for her part of the rescue and, while he can't tell exactly what she did, she would understand what it is about. Arthur goes to thank Morgana, who breaks down crying because she realizes that those weird dreams are actually visions and she also worries that maybe it won't stop with visions and she will get magic as well, but Arthur tells her that she's his sister in all but blood and while there's not much he can do against his father, he will protect her any way he can.
After that Morgana goes to Merlin and thanks him for telling Arthur to thank her because it helped clear up some resentment that had been festering, and in the process also confesses that she might get magic. Merlin assures her that he will stand by her side no matter what, to which she laughs that it's almost the same thing that Arthur said, and Merlin speculates that she sees scenes but not before or after, so those that she doesn't see dead could be saved, that maybe they could even change the future and maybe some enemies only turn against them because she foresaw that they would be enemies and therefore treated them as such.
Arthur has partway through the conversation arrived outside the door and is eavesdropping when Morgana tells Merlin that Arthur also promised to be by her side and Merlin replies "I knew there was something in the prat to be proud of"