King Arthur, the king of all Britain, was showing us his strong power and great castle.
Merlin to the Rescue
Once when King Arthur was wandering in the forest near his castle for a hunt, he met a knight named Pellinor, who had been searching for the Questing Beast for a year.
An Oath to the Lady of the Lake
King Arthur challenged Pellinor in a single combat and they got into a terrible fight.
In the middle of the fight, King Arthur's sword had fallen off his hands and clearly he was about to lose the battle. And then Merlin came and rescued King Arthur by putting Pellinor to sleep with his spell.
After the rescue, Merlin brought King Arthur to a lake, where they met the Lady of the Lake. She was holding a beautiful sword in the middle of the lake. And she said that the sword could be King Arthur's only if he grant a gift or boon in return. Since King Arthur broke his last sword in the fight with Pellinor, he decided to do so.
Look, King Arthur had been out on a journey all day long, and now he's finally back at his great castle again! Except that now he had his new sword, Excalibur, with him.