In a time now lost in the mists of memory, the great King Arthur rules in the legendary citadel that is Camelot. His Knights of the Round Table commit acts of derring-do and spend their spare time jousting, much to the delight of the local citizens and especially to Princess Ilene, a guest at Camelot. Watching her from afar is a young, inexperienced squire called Valiant, and when the young Welsh princess is sent home to marry Prince Arn, Valiant contrives to accompany her masquerading as Sir Gawain. Meanwhile, the evil sorceress Morgan le Fey, sister to King Arthur, has convinced the tyrannical Sligon, ruler of the Viking kingdom of Thule, that he should steal Arthur's sword, the powerful and magical Excalibur, knowing that its loss could bring about Arthur's downfall. So into the fray comes Sligon's unstable and psychotic brother Thagnar, who manages to steal the sword. Pandemonium reigns. But Valiant is having problems of his own - kidnappers attempt to steal away the Princess, and...