Once upon a time, so very long ago that even the great-grandfathers of our great-grandmothers had not been born, there lived in the city of Kwen-lu a little Chinese boy named Pei-Hang.  
His father and mother loved him dearly, and did all they could to shield him from the power of the evil Genii, or spirits, of whom there were a great many in China. Of course, there were some good Genii too, but most of them were very much the reverse, and Pei-Hang's mother was always taking precautions against them.
 
Now it is said that a wicked Geni will not come near a Chinese boy if he has some red silk braided in with his pigtail, or if he wears a silver chain round his neck.
 
And the most daring Geni has a great dread of old fishing-nets.
 
Pei-Hang's mother made him a little shirt out of an old fishing-net to wear next to his skin, and she took care that his pigtail should be plaited with the brightest red silk she could buy.
 
She was particular in having his head shaved in exactly the right way, too, and to have a tuft left sticking up in the luckiest place.
 
With all these precautions Pei-Hang got safely over the troubles of his babyhood, and grew from a little boy into a big one, and from a boy to a tall and handsome youth; and he left off wearing his netted shirt, although the silver chain still hung round his neck and there was red silk in his pigtail.
 
"It is time that Pei-Hang saw a little more," said his father. "He must go to Chang-ngan, and study under the wise men there, and find out what the world is thinking about."
 
Chang-ngan was the old capital of China, a very great city
[279]
indeed, and Pin-Too, the master to whom Pei-Hang was sent was the wisest man in it.
 
And there Pei-Hang soon learned what the world was thinking about, and many things besides. And as soon as he was eighteen he took the red silk out of his pigtail and the silver chain from his neck; for grown-up people do not need charms to protect them from the Genii—they can generally protect themselves.
 
When he was twenty, Pin-Too told him he could not teach him any more.
 
"It is time for you to go back to your parents, and comfort them in their old age," he said.
 
He looked very sorry as he said it, for Pei-Hang had been his favourite pupil.
 
"I will start to-morrow, Master," replied Pei-Hang, obediently. "I will leave the city by the Golden Bridge."
 
"No, you must go by the Indigo Bridge, for there you will meet your future wife," said Pin-Too.
 
"I was not thinking of a wife," observed Pei-Hang, with some dismay.
 
And Pin-Too wrinkled up his eyes and laughed.
 
"All the better!" he said. "Because, when you have once seen her, you will be able to think of nothing else."
 
It was very hot weather, and Pei-Hang ought to have started early in the morning; but he sat so long over his books the night before his journey that he fell fast asleep just before sunrise, and slept all through the coolest hours of the day.
 
When he awoke, the sun was blazing down upon the streets of Chang-ngan, and making the town like a furnace.
 
However, Pei-Hang took up his stick and set off, because he had promised his father and mother to start that day.
 
"I will rest a little at the Indigo Bridge, and walk on again in the cool of the evening," he said to himself.
 
But on the bridge he fell asleep again, so tired was he with the many sleepless nights he had spent in study.
 
While he slept he had a dream, in which a tall and beautiful maiden appeared to him, and showed him her right foot, round which a red cord was bound.
[280]
 
"What is the meaning of it?" asked Pei-Hang, who could hardly take his eyes away from her face to look at her foot.
 
"What is the meaning of the red cord around your foot, too?" replied the girl.
 
Then Pei-Hang glanced at his right foot, and saw that his foot and the girl's were tied together by the same thin red cord; and by this he knew that she must be his future wife.
 
"I have heard my mother say," he said, "that when a boy is born, the Fairy of the Moon ties an invisible red cord round his right foot, and the other end of the cord round the foot of the girl-baby whom he is to marry."
 
"That is quite true," said the maiden; "and this is an invisible cord to people who are awake. Now I will tell you my name, and remember it when you hear it again. It is Yun-Ying."
 
"And I will tell you mine," began Pei-Hang, but Yun-Ying stopped him, smiling.
 
"Ah, I know yours, and all about you," she said.
 
This surprised Pei-Hang very much; but he need not have been greatly astonished, for everyone in Chang-ngan knew that Pei-Hang was the handsomest and wisest and best loved pupil the wise Pin-Too had ever had.
 
And Yun-Ying lived quite close to the city, and had often seen Pei-Hang walking through the streets with his books.
 
When Pei-Hang awoke, he found, as she had said, that there was no red cord around his foot, and no fair maiden looking down at him, either.
 
"I wonder if she is real, or only a dream-maiden, after all," he said to himself.
 
But Yun-Ying was quite real; only her mother, who knew something of magic, had given her the power of stepping in and out of people's dreams just as she chose.
 
Pei-Hang got up and went on his way, thinking of Yun-Ying all the time.
 
It was still very hot, and he grew so thirsty that he went to a little hut by the roadside, and asked an old woman who was sitting in the doorway to give him a drink.
[281]
 
The old dame told her daughter to fill their best goblet with fresh spring water, and bring it out to the stranger; and when the daughter appeared, it was none other than Yun-Ying herself.
 
"Oh!" cried Pei-Hang, "I thought perhaps I should never see you again, and I have found you almost directly."
 
"And what is my name?" asked the girl, laughing.
 
"Yun-Ying," replied Pei-Hang. "Yun-Ying, Yun-Ying," he repeated, in a singing tone, just as he had been saying it all the time as he walked along, as if he loved the sound of it.
 
Yun-Ying was dressed in white underneath, but her over-dress was bright blue, embroidered with beautiful flowers which she had worked herself; and she stood in the door of the hut, with a peach tree in full bloom over her head, making such a picture of youth and loveliness that Pei-Hang's heart seemed to jump up into his throat, and beat there fast enough to choke him.
 
"Who are you? And how do you come to know Yun-Ying?" asked the old woman peering and blinking at him, with her hand over her eyes, to shade them from the sun.
 
And when she heard about the dream, and the red cord, and that Pei-Hang wanted to marry her daughter, she did not look at all pleased.
 
"If I had two daughters you might have one of them, and welcome," she grumbled.
 
For Pei-Hang was not by any means a bad match. His parents were well off, and he was their only child.
 
But Yun-Ying was a very pretty girl, and a mandarin of Chang-ngan was anxious to make her his wife.
 
"He is four times her age, it is true," said her mother, explaining this to Pei-Hang; "but he is very rich. All his dishes and plates are gold, and they say his drinking-cups are gold, set with diamonds."
 
"He is old and wrinkled, like a little brown monkey," said Yun-Ying. "I don't want to marry him! And, besides, the Fairy of the Moon didn't tie my foot to his."
 
"No, that's true enough," sighed her mother.
 
She would have liked to tell Pei-Hang to go about his business,
[282]
but she knew if the red cord had really been tied between his foot and Yun-Ying's, it would not be safe to do that.
 
"Come inside," she said at last; "I'll see what I can promise."
 
The inside of the hut was fragrant with the scent of herbs which were strewn all over the floor, and on a wooden stool in the middle lay a broken pestle and mortar.
 
"Now," said Yun-Ying's mother, "on this stool I pound magic drugs given to me by the Genii; but my pestle and mortar is broken. I want a new one."
 
"That I can easily buy in Chang-ngan," replied Pei-Hang.
 
"No; for it is a pestle and mortar of jade, and you can only get one like it by going to the home of the Genii, which is on a mountain above the Lake of Gems. If you will do that, and bring it back to me, you shall marry Yun-Ying."
 
"Yes, I will do that," said Pei-Hang, after a moment's thought. "But I must see my parents first."
 
He had not the least idea where the home of the Genii was; but Yun-Ying took him out into the garden, and showed him, in the far distance, a range of snow-capped mountains, with one peak towering above the rest.
 
"That is Mount Sumi," she said, "and it is there the Genii live, sitting on the snow-peaks, and looking down at the Lake of Gems."
 
"But to reach it you must cross the Blue River, the White River, the Red River, and the Black River, which are all full of monstrous fishes. That is why my mother is sending you," sighed Yun-Ying. "She thinks you will never come back alive."
 
"I know how to swim," said Pei-Hang, "and fishes don't frighten me."
 
"Promise me you won't try to swim," said Yun-Ying, earnestly. "You would be devoured in a moment. Take this box with you. In it you will find six red seeds. Throw one into each river as you come to it, and it will shrink into a little brook, over which you can jump."
 
Pei-Hang opened the box, and saw inside six round, red seeds,
[283]
each about the size of a pea; and he agreed to use them as Yun-Ying directed. Then he kissed her, and set out on his journey to Mount Sumi.
 
But on his way across the plain he passed through the town where his parents lived, and he went to see them, and told them all that had happened since he left Chang-ngan.
 
His mother, who was a very wise woman, as mothers generally are, told him the Genii would be angry if he turned their four great rivers into brooks, and would probably refuse to give him a pestle and mortar made of jade.
 
"I never thought of that," said Pei-Hang.
 
"Never mind," said his mother, "I will give you a box containing six white seeds. Cast one into each brook when you have crossed it on your way home, and the brook will expand into a river again."
 
Early the next morning Pei-Hang kissed her and went on his way.
 
He rested during the midday heat, and continued his journey when it grew cool again; and in this way, at the end of seven days, he came to the Blue River.
 
It was a quarter of a mile wide, and as blue as the sky of midsummer, a............