A scientist performing illegal stem cell research is trying to find a cure for cancer. After the transfer of shark cells is made into a human test subject, the ill man gets well again and it looks like the treatment was a success. But the experiment goes wrong, and the man transforms into monster half-shark half-human. But the scientist knows how to use this to his advantage. He has invited some of his old pals to the island and is hoping to take revenge on them with his new creature. But do they have any tricks up their sleeve

毒贩克里斯的妻子带走了三百万美元和他们的儿子逃跑，克里斯在打探妻子下落的过程中枪杀了一名知情者，这起凶杀案令追查了克里斯多年的警探金宝（阿诺·施瓦辛格 Arnold Schwarzenegger 饰）终有机会将其收押，然而如令克里斯认罪伏法，金宝还必须找到他的妻子作为重要证人。警方掌握的线索及其有限，金宝和女同事只得来到某小镇，卧底装扮成老师来寻找就读于幼儿园的克里斯之子。因女同事急病，金宝只得独挑重任，和一群十分不安分的小鬼头打交道，同校的女教师乔伊丝（佩内洛普·安·米勒 Penelope Ann Miller 饰）和金宝之间擦出了火花。金宝的教师生涯渐渐顺风顺水，而这时，克里斯妻子与儿子的身份浮出水面，令金宝颇感意外……