The letter.

Jon wanted to become a cop. When he went to apply they gave him a note showing an address. They told him that he must go there for a beginners test before they would hire him.

Once he arrived the leader told all the people the instructions. They would each be given a letter to deliver to the 20th floor. Then they warned them that under no circumstances may the letter be opened. 

However, Jon was curious so he slipped into a hallway and opened the letter. This is what it said: 


You have the qualities to be a police officer. Please deliver this letter to the third floor instead to begin your training.

Written by Skyrim90000