Once upon a time...
There was an old king who was so ill that he thought to himself, "I am most likely on my death-bed." Then he said, "Send Trusty John to me." Now Trusty John was his favourite servant, and was so called because all his life he had served him so faithfully. When he approached the bed the King spake to him: "Most trusty John, I feel my end is drawing near, and I could face it without a care were it not for my son. He is still too young to decide everything for himself, and unless you promise me to instruct him in all he should know, and to be to him as a father, I shall not close my eyes in peace." Then Trusty John answered: "I will never desert him, and will serve him faithfully, even though it should cost me my life." Then the old King said: "Now I die comforted and in peace"; and then he went on: "After my death you must show him the whole castle, all the rooms and apartments and vaults, and all the treasures that lie in them; but you must not show him the last room in the long passage, where the picture of the Princess of the Golden Roof is hidden. When he beholds that picture he will fall violently in love with it and go off into a dead faint, and for her sake he will encounter many dangers; you must guard him from this." And when Trusty John had again given the King his hand upon it the old man became silent, laid his head on the pillow, and died.