Herrington Hill seems to be an American school like others. Scaled walls, used professors and demotivated pupils constitute the sceneries of the establishment. But the general apathy is quiclky going to leave place for nightmare.
Everything begins when Casey, the whole high school picks on him, discovers a sort of insect larva on the football field. Confided to his biology professor, the thing has the particularity to resume life when it is dived into the water. Later Casey and the journalist in herb Delilah are witnesses of the murder of the nurse Harper by professor Willis, the trainer of the football team, and Miss Olson. After having warned the police, the affair is closed; the nurse is well alive and in perfect health.
Nevertheless the strange behavior of the professors seems to gain all the pupils of the high school. They attempt to warn their friends Stan, Stokely, Marybeth and Zeke that aliens have taken human form so as to take slyly control of the Earth. First incredulous, they radicallty change their mind when they are witnesses of the transformation of the biology professor. Zeke, little dealer, kills the impostor by injecting him a drug of his own manufacture.
They All escape and find refuge in Zeke's apartment, escaping to the barrages of policemen now infected by the small larvas that take the control of their body.
Thanks to the instruments present in his apartment transformed into real clandestine laboratory, Zeke studies the specimen taken by Casey. He discovers that it is an incomplete parasite that lives in a host and belongs to a greater organism.
It is capable to reproduce, but it needs something wet. In fact, the alien parasit uses the human body humidity to survive. These small shits have invaded the high school in a day and a half.
Rapidly, they begin to suspect each other to shelter one of these specimen. To re-establish the confidence, Zeke proposes to make a test. Knowing that his drug is suitable to make react the aliens, he invites each to inhale an individual dose. The test is conclusive since Delilah, invaded by the thing, reacts and escapes.
Specialist in science fiction, Stokely thinks that it would suffice to destroy the queen to get rid forever of the extra-terrestrial invader. This friday evening, the queen certainly assists to the football match where is gathered all the city. Thinking that the Principal Drake shelters the queen, our five students kills her by injecting her Zeke's drug. But while going to verify the efficiency of their action, Stan is to his tour infected...
Spoiler ! the end of the story is revealed below…
With the assistance of Casey, Zeke leaves to seek the last drug doses in the box of his car while Stokely and Marybeth remain hidden in a gymnasium. This last unveils her real nature and transforms into an giant terrifying beast. After a long fight, Casey the last healthy human will have reason of the monster. As Stokely had anticipated it, larvas present in infected bodies leave their hosts and everyone recover his real nature. One month later, the life has resumed in Herrington Hill, but Casey has become a real hero.
Amateurs will easily recognize in "The Faculty", an homage to "John Carpenter's Thing", particularly during the test undertaken to determine who is contaminated and who is not, and especially to "Invasion of the Body Snatchers", realized in 1956 by Don Siegel that "The Faculty" is a nowadays adapted remake.