While the hot rodders and motorcyclists are having a rock-and-roll beach party, a barrel of radioactive material is unloaded from a passing ship, plunges to the bottom and splits against a jagged rock. A black liquid oozes out and covers a shapeless mass on the ocean floor, which suddenly moves and becomes an encrusted vicious monster. Soon there are several monsters and they must have human blood to survive. Tina is the first victim, and football hero Hank Green and airhead Elaine Gavin enlist the aid of her science-professor father, Dr. Gavin, to solve and capture the killer. Not working fast enough to prevent the attack on twenty teen-agers at a slumber party nor the killing of three girl motorists, Dr. Gavin finds an arm lost by one of the monsters and discovers that only sodium will destroy the monsters whose composition is mostly water. Can they gather enough salt in southern California to put an end to this horror?

警探本•卡森（Kiefer Sutherland 基弗•萨瑟兰 饰）因枪杀同事被迫从纽约警察局提前退休，他的婚姻也随之破裂。落魄的本暂住在妹妹安琪（Amy Smart 饰）的公寓里，终日借酒浇愁。一段时间沉沦过后，本重抖精神，找到了一份保安的工作。他所供职的五月花购物商场五年前曾被大火毁于一旦，令他倍感奇怪的是，在这座焦黑的建筑物中，那一面面镜子却格外明亮。
　　数日后，本在商场的镜子上发现奇怪的手印，而次日亦在妹妹家的镜子上见到恐怖的景象。接下来的日子里，恐怖事件接连发生……

皮帕和托马斯搬进了他们梦寐以求的公寓，他们注意到他们的窗户正对着对面的公寓——邀请他们亲眼目睹街对面这对迷人夫妇的不稳定关系。但当他们试图以匿名方式介入他们的生活时，他们不知不觉地引发了一系列将导致灾难的事件。

　　前警探艾德蒙在六年前的一场肇事逃逸中，不仅丧失妻子朱丽叶，终身必须在轮椅上度过。杀手迟迟未找到，艾德蒙也在20岁温顺女儿夏洛特的照顾下生活，努力找寻凶手，却也将这一切意外怪罪于夏洛特身上。某天夏日，一个懊悔又心碎的陌生人前来拜访，自称是意外事故的司机希望能得到原谅或惩罚。在找到凶手后于了解事情的全面，问题是艾德蒙无法逮捕他，不愿让六年的苦心白费，艾德蒙开始设计一场涉及司机、女儿还有他自己的危险计划。随着计划逐渐失控，罪恶、欲望及怨恨也突破表面……

一对情侣来到林间小屋却意外遭到了凶恶歹徒的袭击，并在逃跑过程中被绑架囚禁。她们发现被囚禁的不止她们，歹徒也不止一人。她们必须为了活下去进行反击...