Cox's fairytale begins with the usual suspects lined up and dressed for the occasion. Once upon a time on the outskirts of a village called Sacred Heartily, Princess Elliot needed help with her maid Marion. The village idiot, J.D., arrives to assist, bragging of his bravery in saving a fish from drowning. The Princess explains that her Maid Marion is suffering from a monster disease. Turkala, a two headed witch, then appears, offering help. The witch tells the Princess and the idiot to meet her at the village drug store for a magic potion.
The story continues as the idiot and the Princess ride to the village on a mule where the Dark Lord Oslek appears and warns, "Everyone who enters the forbidden forest shall disappear!" Back in the hospital, Doug stays longer than his shift and is "banished" home without pay. Elliot and J.D. ask Turk and Carla if the lab results for Marion are back. Carla has worked some magic and hands the results over â€" they are negative. Elliot still doesn't know what is wrong with Marion.
Back in the story, Princess Elliot uses a dove to "page" her handsome Knight Percival Cox. Her savior arrives and fights the monster disease with his sword but is foiled when the witch Jordan interrupts and turns out the light. Unable to finish the story, Cox sneaks back into Jack's room to complete the adventure. The knight Cox is defeated by the monster disease, but tells the Princess and the idiot the monster can only be vanquished by a gold ring.
In the forbidden forest the giant tells Princess Elliot and J.D. the Idiot that evil Oslek will catch them as he is near. In the hospital, J.D. and Elliot are hiding from Kelso after their shift ends, but he catches them and banishes them to his office where he threatens to suspend them. Back in the forest, the Princess and the Idiot look for the gold ring but can't find it.
J.D. remembers the interns playing diagnosis Jeopardy. The answer to their quiz is the answer to Maid Marion's disease. The Princess and Idiot find the gold ring and race through the village to save Maid Marion. Back at Sacred Heart, J.D. examines Marion's eyes. Seeing a gold ring around her retina, he diagnoses Wilson's Disease. They are now able to treat her and all hopefully live happily ever after.