在大公司纽斯特德的支持下，生物科学家克里夫·尼科利（阿德里安·布洛迪AdrienBrody饰）和女友艾尔莎·卡斯特（萨拉·波莉SarahPolley饰）进行基因重组的实验，并取得初步进展。然而由于资金和公众舆论等原因，纽斯特德高层决定中断对他们现有研究的支持。克里夫和艾尔莎不愿半途而废，于是偷偷展开实验。他们对基因进行优化重组，并混入了艾尔沙的一部分基因，终于孕育出一个相貌奇特的雌性怪物。

Thenightmarewasaboutademonicpossession.Alongtimeago,therewasanevilinasmalltownanditwasjealousofthegirlandwouldneverlethergo,sincethedevillovedthegirl.Onenight,theevilrapedthegirlandshebecamepregnant.Aftermonthsthegirlcouldnothideherbaby,herfatherfiguredhersecretoutandclappedthegirlinironsandlockedherroomdoor.Buttheevilputtheguntoherfather'templeandsavedthegirl.Thefatherhadastrokeandhadbeensleepingonthebedforthreemonthsanddied.Timewentonandthegirlbroughtachildintotheworld.Naturally,peoplewhowerelivinginthevillageheardthestoryandtheydidnotwanttoseeneitherthegirlnorthebabysincewhenthebabywasborn,plantsdriedinthefield,fisheslostinthelakeandpeoplehadprayedtothegodforrain,butnothingchangedinthevillage.Peoplegotsoangry,dugaholeinfrontofthefountain,putherintotheholeandthrewstonesatherface.Thegirldiedsoonafter.Theevilwentoffthedeepend,tookarevengeofthevillageandkilledeveryoneexcepttwosistersbecausetheevilwantedthemtotakecareofitsbaby...