LindahasaseeminglyperfectmarriagewithherruggedandhandsomehusbandMarkandanadorable8yearolddaughter,Chloe.ButwhenChloeisinjuredbyanelderlybabysitterwhohasslippedintodementia,Lindawantstoensurethatherchildisneverhurtagain.Initially,Heather,thenewbabysitter,seemsliketheidealadditiontothispracticallyperfectfamily.ButHeatherisaschemerwhoexploitsthecracksinMarkandLinda'srelationship,anddelightsintheresultingchaos.AsLindalaterlearns,toherhorror,Heather'sintentionsgofarbeyondthemischievous.
与虐待成性的丈夫分居后,一位前戏剧演员拼命地乔装改扮,试图与她唯一的孩子共度时光。