Merlin saves a Druid girl from a bounty hunter's cage, but there is more to her than meets the eye.

The new queen of Camelot proves to be far crueler than Uther, who is made to watch from his dungeon as she slaughters innocents. Guinevere helps Sir Leon escape from prison and joins her brother Elyan, Gaius, Merlin, Arthur and Gwaine, who are hiding in the woods. Soldiers follow but they are saved by Lancelot and a youth of immense strength, Percival. Merlin looks into the waters of Avalon in the phial given him by the Fisher King, which directs him to Excalibur, the sword which will defeat the enemy. The fugitives find a round table, around which they movingly declare allegiance to each other, and Arthur knights all the young men - except, of course, Merlin, though Lancelot, aware of his powers, tells Merlin he is the bravest of them all. The group launches its invasion of Camelot, which gives Gaius his finest hour as the sisters are routed, largely due to Merlin's use of Excalibur. However, he places the sword in a rock until it can be used again.