Invisible
"Your turn."
The man being spoken to, a security guard, then attempted to guess what was on the card on his forehead while the on speaking timed him. He was a scientist that worked at the college. They were playing inside the professors study a very basic office with many abnormally large binders labeled 1-9, number 10 was on his desk.
Suddenly, there was a knock at the door and the guard shined his light through the window, seeing no one was there he returned to his seat saying "Eh kids."
Then the door opened but no one came in. Next, to the guards surprise, a pen on the desk got up, the binder labeled 10 opened and the pen on the last page wrote 'success'. The pen dropped to the floor and footsteps were heard running out the door. But as they passed through the doorway a man flickered in and out of existence.
The security guard looked toward the scientist for an explanation but he was gone. The silence was broken by the slam of the office door.
Oo0oO
The following day's campus paper's main article was "Security Guard Contained In Mental Institution".