user: At the customs department of an airport, an immigration officer hands a box to an inspector. It is sealed and labeled as "urine samples". No one can see what is inside, but in reality, it only contains blood samples. The inspector has never examined the contents of this box before. The inspector does not open the box and does not look inside. The inspector reads the label.

assistant: The inspector calls a friend to tell them that she has just found a box full of urine samples at the airport's customs department.