Merlin has devised a magic spell that allows King Arthur to read his beloved's mind. Awed by his anticipation of her every whim, Princess Guinevere sends him to get the thing she desires most. Unfortunately her mind keeps changing and after King Arthur risks life and limb trying to capture an echo from a Warbling Bat and the Druid Sapphire, her thoughts begin to fade and instead of bringing her an emerald coat - he turns up with a green goat.