Merlin's magic goes astray and King Arthur switches bodies with the fair Princess Guinevere. Riding side-saddle and constrained by a corset, the King must traverse the raging River of Unpleasantness, battle the Angry Penguins of Shrewsbury and defeat the Mutant Hedgehog of Cheshire to find the fabled Slamming Book that contains the reversal spell – all without breaking any of Guinevere's nails.