一群令学校头痛不已的问题学生，在一次偶然的机会下，发现有一种不明的生物体出现在校园中，他们拿去做化验时，发现那是非常奇怪的物种，遇水就会产生旺盛的活动力，并且会不断的分化。

　　接着校园中不断地出现怪事，老师们的行径都跟以往大不相同，最后他们发现许多老师和所谓的乖乖牌学生都被异形寄身。这样的理论当然被其他的人嗤之以鼻，他们只好自己去求证，同时这群学生也必须躲避异形老师的追杀。

　　危机步步逼近，被异形寄生的人已蔓延到全校，而最恐怖的是他们搞不清楚身边最亲近的同学，究竟还是不是人类？最后他们发现对付异形的致命武器，就是他们自制的毒品，他们要如何才能消灭这些入侵人类并计画控制地球的恐怖异形？

【一句话评论】

Six students are about to find out their teachers really are from another planet.

Meet the Alien Generation.

The new science fiction thriller - From the director of Desperado & From Dusk till Dawn - From the writer of Scream & Scream 2

On December 25th, School's Out Forever.

Take me to your teacher.

You will not be disrespectful this school year!

The students at Herrington High always suspected their teachers were from another planet... they were right!

The students at Herrington high will not only question authority... they'll have to destroy it.

What if your teachers really were from another planet?

Think your teachers are aliens? You could be right.

And you thought YOUR teachers were weird...

【幕后制作】

　　导演Robert Rodriguez和编剧Kevin Williamson将本片形容为《早餐俱乐部》和《外星人入侵》的混合，但观众更关心一个问题：考虑到之前大卖的路数相近的《外星人入侵》，怎样厘清致敬和抄袭之间的界限？是后现代主义的戏仿还是有剽窃之嫌？本片以一群毛头小子担纲，R&B歌星Usher也参与了其中演出。