The plot tells the story of a group of children exploring and tracking a medieval scourge named Morgana, who is King Arthur's half-sister. Lewis plays Alex, who accidentally discovers King Arthur's holy sword "Excalibur", Taylor plays his companion Lancelot, Denise Gough plays his mother, Imrie plays the young version of Merlin, Stewart is expected to play the old version of Merlin, and Ferguson is expected to play the villain Morgana. The film is distributed by Fox and is full of action-adventure elements.