A character who's motives are completely driven by vengeance. Edwin Muirden's goals are to get rid of Gaius and kill Uther all because Uther had his parents killed as sorcerers and Gaius did nothing to stop it.
Edwin worms his way into the court by getting Morgana sick and then miraculously curing her. He of course has inherited his parents magical skills and figures he can kill Uther and bring back magicians to the world of Camelot. Edwin becomes aware of Merlin's skills and tries to win him over by helping him as a mentor. When Gaius recognizes Edwin for who he is Edwin threatens Gaius with Merlin's life.
While in the glow of the courts gratitude over saving Morgana, Edwin puts doubt in Uther's mind about Gaius and his competency. Of course Uther seems to have a rather simpletons mind to be King. After 25 plus years of services to the court Uther puts Gaius out to pasture and puts Edwin in as the Court Physician.
Gaius to save Merlin excepts the release and decides to leave Camelot. Edwin quick to grab power as soon as possible immediately tries to kill Uther. He poisons him with a potion that paralyzes him. Then implants a beetle to slowly kill him.
Gaius returns to stop Edwin but Edwin is stronger than Gaius. Merlin is stronger than Edwin and when Edwin tries to kill Gaius and then Merlin, Merlin kills Edwin with Edwin's own weapon.
Merlin saves Uther with magic and of course Uther grants Gaius his job as Court Physician back and gives Gaius a scroll as a free man because he believes Gaius saved him.
An interesting study in perception is reality. Uther is so caught up in magic=evil that he "realizes that Gaius is the one person he can trust to save Camelot from magic". Ironic!
Enjoyable episode. Great series. Terribly under viewed. Thanks for reading...