How to mess with teachers: A freshperson's guide

In ToK a little while ago, Miss Davey was (for once!) on time to class. She's famous for being a bit unorganized, but only because that's how she functions best. I get the impression that she shares my trait of appearing to be entirely unorganized, but actually can produce whichever form or paper is requested of her from her messy-looking pile without too much trouble. Anyway, she's also known for usually being a couple of minutes late to class, what with having to come from classrooms all around the school. This particular class, however, this was not the case. She proudly arrived about two or three minutes before class was to start, vowing that she would never be late again. She then told us this story:

A short time before the events of the previous paragraph, Miss Davey's organizational skills had gone completely wrong. She ended up being about twenty minutes late for her next class, which was a ninth grade class. During this time, the ninth graders in the class had decided to play a little trick. When she finally arrived, she found every desk in the room turned upside down. They were however still positioned in rows, as always, and there was a freshperson with a notebook patiently awaiting her arrival in each one, ready to take notes on the day's lesson.

She ended the story by promising never to be late again. I give her two days. Miss Davey, if you read this, you may consider that a challenge.