4. Change takes place in Excalibur, Season 1 Episode 9.
Merlin goes to present the sword to Arthur in his chambers instead of waiting for him in the armory. Upon finding the prince asleep, Merlin wakes him with a small spell. Delivering Arthur the sword that was burnished for the Once and Future King, when he fights the black knight, Arthur is set on a much quicker path to becoming the man the legends dream of. The dragon never demands the sword be hid, and, through the sword, Arthur begins to see the world around him for what it truly is.