Sam, Lucy, and Antonio have a new substitute teacher, who happens to be the great-great-grandson of Orson Eerie, the evil scientist whose spirit possesses and infects their elementary school--and the friends are afraid he may be trying to bring Orson back to life.

At the end of recess at Eerie Elementary, everything on the school grounds suddenly comes alive and turns into a fog-filled jungle maze intent on trapping and disposing of hall monitor Sam Graves and his friends Antonio and Lucy.