Max and Olivia have discovered that Morgana Le Fay is plotting to use a mysterious Swordspell against King Arthur at the Festival of Chivalry. They don't know what the spell is or how to stop it, and Olivia also has her training for the Squire's Challenge to worry about.
Things are made even worse when Merlin is called away unexpectedly, leaving Max and Olivia without his magical protection. With the help of Sir Lancelot, Sir Bertram and Adolphus the dragon, Ferocious the rat and Vortigern the duck, the Pendragon children must uncover Morgana's evil plan . . . before it's too late for Arthur and Camelot.