S1, E2: A knight named Valiant arrives to compete in a sword-fighting tournament. Valiant holds in his power an enchanted shield which causes great harm to his opponents. Merlin's attempts to warn everyone fall on deaf ears - and Arthur is next to face Valiant. With a shield bearing enchanted but hidden snakes who await only his command to strike, the Knight Valiant rides into Camelot to compete in the annual sword-fighting tournament. As Arthur prepares to fight Valiant in the final, a disgruntled Merlin, still getting to grips with his many arduous duties as Arthur's new servant, discovers that Valiant is cheating. If Valiant unleashes the magical snakes upon him, Arthur will surely die. Merlin presents his evidence to Arthur, who has not exactly been impressed with Merlin's lack of talent for his new job. Arthur is initially dubious, but takes a leap of faith and decides to trust the youthful Merlin. Arthur makes his case to his father King Uther before the entire royal court, but is forced to withdraw the allegations. With his father disappointed in him, Arthur blames Merlin for his humiliation and dismisses him. Realising that he must master the magic that brings the snakes to life so he can expose Valiant and save Arthur, Merlin struggles through the night trying to learn the incantation. On the day of the tournament final, Merlin is running out of time...As Arthur fights Valiant, dodging snake bites from the magic shield, Merlin finally masters the magic. He races to the amphitheatre and uses his own powers to expose Valiant by revealing the snakes to the world. But is Merlin too late to save Arthur, and will his own magic abilities be revealed?