Gilli, a young boy, wends his way towards Camelot to take part in the legendary tournament. On the way, two thugs, Nollar and Tindr, make fun of his wiry stature, mocking his desire to compete in the tournament. After they leave, Gilli pulls out a gleaming ring from his bag- could this ring be more than a pretty piece of jewellery?
The next day, Merlin is cleaning Arthur's armor when he is cornered by Tindr and Nollar, who attack him. Gilli leaps to Merlin's defense, and manages to turn the scuffle to his and Merlin's advantage. Merlin notices the ring on Gilli's hand and is convinced that the boy is using magic. The two boys form a bond as Merlin thanks him for rescuing him.
Meanwhile, in the castle, Morgana convinces Uther that he is still young and strong enough to enter the tournament...the King, fondly remembering his youth, agrees to enter. Arthur, however, is worried about his father. This is, after all, a dangerous tournament with no rules, but we see Uther defeating opponents with skill and bravery. Arthur also advances, overcoming the contestants with his usual aptitude on the battlefield.
It is Gilli's turn. He faces a huge man, who savagely attacks, and it seems that the slight boy is no match for this beast. The crowd jeers, but then the tide turns and Gilli manages to defeat his opponent. The boy is forced to use magic to heal himself, but the bright white light emitted by his spell is seen by the Camelot guards. They chase Gilli, but he manages to escape.
The next day, Uther examines the scorch marks left behind by Gilli's spell, and Gaius spies the magic ring on the ground. Worried for Gilli's safety, Gaius urges Merlin to talk to his new friend. Merlin confronts Gilli and says he knows he used magic to win the fight. Gilli tells Merlin that his father was a sorcerer, and was killed by Uther's men. Merlin advises Gilli to withdraw from the competition, because if he continues to use magic he will be caught and executed.
Uther is still in the competition and Arthur, too, faces each strange and dangerous competitor with courage. With a sinking heart, Arthur realises that the time has come to face his father in the next round. Arthur wrestles with the idea: should he go through with it? For Morgana, this is going entirely to plan...she hopes that Uther will be killed.
Arthur and Uther fight. At first, it seems like Arthur is winning, but then Uther gains the upper hand and pins Arthur to the floor. The King has won and the crowd go crazy. Morgana is annoyed, as neither man has been hurt.
Gilli also defeats his opponent and progresses through to the next round. Gaius pressures Merlin into forcing Gilli to withdraw again. This time, Merlin reveals that he has magic too, in order to convince Gilli to use his magic for good, not evil. Gilli, however, refuses to abandon the competition.
The day of the final. Merlin uses his magic to leave Gilli defenseless in front of the king. Uther then defeats the boy, and the King is victorious. After the fight, Merlin apologises to the angry Gilli, who realises that he was using magic for an evil purpose and that magic can be corrupting. The two boys are friends again.
In the palace, Uther is regaling all with his feats of strength in the tournament, but then he admits that he knew that Arthur let him win, and that this gracious action demonstrates Arthur's readiness to be King. Gaius is proud of Merlin for his behaviour, and the two playfully joke around together. Harmony is restored between the physician and his apprentice, and all is well.
Merlin has pushed the limits of his strength to save Arthur, but even he may not be powerful enough to rescue Camelot€™s king.
In the battle foretold by the prophecies, all give their best, and Merlin wins the day.
Morgana may have one last trick up her sleeve to win the war.