Once there was a poor farmer named Crabb. One day, he took a load of wood to town and sold it to a doctor for two pieces of silver. While the doctor was paying him, Crabb saw the doctor sitting at a table filled with delicious food and drink. Crabb thought, "I would like to be a doctor, too."
He asked the doctor if he could learn the profession.
"Oh, yes," the doctor said. "That is easy. First, buy a book for learning to read—the kind with a picture of a rooster in it. Second, sell your oxen and your cart to buy some nice clothes and medical tools. Finally, paint a sign that says, 'I am Doctor Knowall,' and hang it above your door."
The farmer did exactly what he was told. Not long after he started his new job, a rich lord had some money stolen. The lord heard about "Doctor Knowall" and went to find him.
"Are you Doctor Knowall?" the lord asked.
"Yes, I am," Crabb replied.
"Then come with me to my castle and find my stolen money."
"I will come," said Crabb, "but my wife, Grete, must come too."
The lord agreed, and they all drove to the castle. When they arrived, a grand dinner was ready. The lord invited Crabb to eat. "My wife must eat with us," Crabb insisted, and they sat down at the table.
When the first servant brought a dish of food, Crabb nudged his wife and whispered, "Grete, that was the first." He meant it was the first course of the meal.
However, the servant had actually helped steal the money. He thought Crabb meant, "That is the first thief." He was terrified and told the other servants, "The doctor knows everything! He said I was the first."
The second servant was afraid to go in, but he had to serve the second dish. When he entered, Crabb nudged his wife and said, "Grete, that is the second." The servant ran out as fast as he could. The third servant had the same experience.
For the fourth course, the servant brought a covered dish. The lord wanted to test the doctor. "If you are so wise," the lord said, "tell me what is under this cover."
The dish actually contained crabs. Crabb looked at the dish and didn't know the answer. He sighed sadly and said his own name: "Ah, poor Crabb!"
When the lord heard this, he cried, "He knows! If he knows there are crabs in the dish, he must know who has the money!"
The servants were now shaking with fear. They secretly asked the doctor to step outside. They confessed to the crime and offered him a large reward if he didn't tell the lord. They showed him exactly where the money was hidden.
Crabb was satisfied. He went back to the table and said, "My lord, I will look in my book to find the gold."
Meanwhile, a fifth servant had hidden inside the large stove to listen. Crabb opened his book and turned the pages, looking for the picture of the rooster. Because he couldn't find it quickly, he said aloud, "I know you are in there, so you might as well come out!"
The servant in the stove thought Crabb was talking to him. He jumped out in terror and shouted, "This man knows everything!"
Doctor Knowall showed the lord the hidden money but did not name the thieves. He received a great reward from the lord and more money from the servants for keeping their secret. From that day on, he was a famous and wealthy man.