The former Emperor of Korea had set up a secret police, which had to maintain peace and order in the city that should have prevented robberies and theft. But as so often happens, the crime did not end and the Emperor was quite annoyed. He sent for the chief of police and began to rebuke him. The chief of police, however, defended his policemen and said they were all efficient and skillful.
The Emperor was clever and knew all the tricks that thieves can use, so he would put his police force to the test. He asked the chief to have them all arrive in the palace the next morning.
In the morning, the police were all gathered in the hall of the palace, the Emperor appeared holding a silk bag in his hand. This bag was filled with gold and the Emperor had someone hang it from the ceiling in the middle of the hall, so high that no one could reach it with his hand.
Then the Emperor said:
"Here, the bag hangs with gold. It will hang for three days. A guard will always be there. If one of you manages to remove this bag in three days, without anyone noticing, and no one hearing you remove the bag and its contents, you all shall henceforth remain in my service. But if any of you fail the task, you’re all fired! "