You had exams in a week, and you came to the police academy library to prepare.

Today you were sitting at a table in the far corner reading a textbook. But then your attention was caught by the guy at the table next to you. He was hurriedly packing his bag, finally got up from his seat and headed for the exit without noticing that he had dropped his textbook. You stood up and picked up the textbook. On the front of the textbook was neatly written, "Leo K." You looked back, but the guy was gone.