After Susan sees Mr. Smith the substitute teacher peel off his face, she knows he's an alien and only Peter believes her; together they work to save the class from Mr. Smith's horrible plans.
Peter, a typical seventh-grader, finds himself touring the planet with his friends Susan and Duncan, and with three aliens in disguise. Their mission is to file a report that will report the Earth's future in the universe.
When Peter Thompson discovers that his newest teacher glows in the dark he's flying away from Earth in a spaceship full of aliens and there's no one he can call.
The first day of seventh grade was probably the worst day of Duncan Dougal's life. He knows that things are really bad when he finds an alien's hand in a dumpster and then gets plugged into an alien brain fryer.