Smith, one of the substitutes, hastily stuffed the test papers into his leather case. School had just gotten out for the week and the teacher's lounge was crammed with desks. Most were empty, everyone else having gone home. Smith took out a small device from inside his pocket. It was a basic scanner, able to read life signs from 500 yards. It was also capable of telling what species the life sign belonged to.
So he was pleasantly surprised when it couldn't match the life sign with any known alien being. Smith, the current alias for the doctor, suspected it to be one of the teachers as the signal was strongest inside the teacher's lounge. Right now the lounge was only occupied by 5 staff members, including himself. He set the scanner down and waited for one of the others to make a move.