During a visit to friends, Sara begins having visions and is attacked by an unearthly creature in her friend's swimming pool| she soon discovers that anyone who comes into contact with the water is in danger and she is driven to confront the mystical and malevolent creature lurking in the depths.。美国国防部研制秘密武器X-Corp,这是部半人、半机器的实验性武器,利用针状抗生物质的传播媒介进入人的神经系统,进而控制人。但后来武器项目失控,半机器人开始袭击人类,并席卷全球,人类陷入末日境地。一群幸存者小分队肩负起拯救人类的使命……。