While being chased by Robin Hood and his merry band, King Arthur stops at the tower to woo his lovely Princess and pick up her latest order. She wants her slipper turned into gold. Merlin knows where this can be arranged and he and Arthur travel to the Fountain of Oro, which lies at the centre of the Labyrinth of Lost Souls. Once in the Labyrinth, they are beset by falling rocks, trap doors, snake pits and scampering little Cornish gnomes - but by far the greatest danger comes from the noxious green smelly gas that emits from Guinevere's shoe...