At the western end of Pienchow during the T'ang Dynasty (618-907) was an inn called the Wooden Bridge Inn. The innkeeper, a Mistress Tertia, was in her thirties and lived by herself, with neither children nor relatives.
Although her inn had only a few rooms and she made her living as a taverness, she was quite well off and owned a great many donkeys. If any of the vehicles passing by needed a change of animals, Mistress Tertia would supply them at a low price. People said she was "a good sort," and travelers from both far and near stayed at her inn.
It was during the Yuanho period (806--821) that a man from Hsuchow named Chao Chi-ho stopped at the Wooden Bridge Inn on his way to the eastern capital of Loyang. Six or seven guests had come before him and taken the other beds, so Chao, as the last to arrive, was left with the one in back, next to the wall that separated the guests' room from their hostess'. That evening, Mistress Tertia served her visitors most generously, and they drank and made merry until late in the night.
By midnight the guests, drowsy with drink, had all retired, and Mistress Tertia had gone to her room, shut the door, and extinguished the lights. Everyone was sleeping soundly; only Chao tossed and turned and couldn't get a wink. Deep in the night, he heard through the wall a slight rustling sound, as though Mistress Tertia were moving something.
Peeking through a crack in the wall, he saw her take down a candle and trim it brighter. Then from a small box she took out a plow, a wooden ox, and a wooden figure, each about six or seven inches in size, and placed them in front of the stove. She spit some water on them, and they began to move. The wooden figure set the ox under the plow, and they started plowing back and forth in front of the bed. Mistress Tertia next took from the box a packet of buckwheat seeds, which she gave to the little man to plant. In no time at all the seeds sprouted and grew into ripe buckwheat. The little man harvested seven or eight measures, set up a small mill, and began to grind the wheat. When the wheat had all been ground into flour, the woman set the wooden ox and the wooden figure back in the box and baked the flour into biscuits.
After some time the cocks crowed and the guests prepared to depart. Mistress Tertia had risen first, lit the lamps, and set the newly made biscuits on the table as breakfast for her guests. Sensing something amiss, Chao quickly excused himself and left, hiding outside the door to peer in.
As he watched, the guests at the table had not yet finished eating the biscuits when they fell straight to the floor, braying, and turned into donkeys. Mistress Tertia drove the donkeys behind the inn, and appropriated the guests' possessions.
On his way back from Loyang a month later, before he came to the Wooden Bridge Inn, Chao prepared some buckwheat biscuits the same size and shape as those he had seen there earlier. When he got to the inn, Mistress Tertia was as glad to see him as before, and because there were no other guests that evening, she treated him even more generously. When it grew late, she inquired solicitously whether he needed anything, and Chao asked her to prepare a light breakfast for him in the morning. "That's no problem," Mistress Tertia replied. "Just get a good night's sleep."
Sometime past midnight, Chao peered in and watched her do exactly as before. At daybreak, after she had set out the plateful of biscuits, Mistress Tertia went to fetch something. This gave Chao a chance to remove one of her biscuits and replace it with one of his own without her knowing.
Chao came to eat before leaving. "I happen to have some biscuits of my own," he told Mistress Tertia. "Please save yours for other guests." He then took out his biscuits and began eating them, while Mistress Tertia went out to bring him some tea.
"Please give one of mine a taste," he begged her when she returned, handing her the biscuit of hers that he had removed before. As soon as she bit in, she let out a bray and turned into a donkey--and a good, strong one at that. Chao seized the wooden figures, but he lacked the knack and couldn't get them to work, try as he might.
Chao whipped and rode the transformed donkey all over the country, yet it still covered a hundred miles a day without faltering. Four years later, four or five miles east of Huayueh Temple, he came upon an old man by the side of the road who clapped his hands and burst out laughing. "Mistress Tertia of Wooden Bridge Inn," the old man exclaimed, "how ever did you wind up in a shape like this!" Grabbing the donkey, he turned to Chao: "Even though she did wrong, she was really out of luck to meet up with you! Have a little pity and let her go."
The old man ripped the donkey's skin back from its nose and mouth, and Mistress Tertia jumped out, the same as she had been before. Bowing in thanks to the old man, she departed, no one knows where.
This story is taken from a book of strange tales from the T'ang Dynasty called Hotung chi. Characters with mysterious origins or destinations are not uncommon in T'ang wonder stories.