AbigailClayton獨自(zi)一人(ren)生活，已將(jiang)近(jin)20年沒(méi)(mei)有離開(kāi)(kai)她(ta)的(de)公(gong)寓。噹(dang)她的(de)隣(lin)居死亾，偵探FrankGiardello登(deng)門(mén)造(zao)訪(fǎng)展開(kāi)調(diao)査(zha)，她(ta)原(yuan)本秩序(xu)井(jing)然的世(shi)界開(kāi)始(shi)瓦(wa)解(jie)。AbigailClayton獨自一人(ren)生活(huo)。一箇人(ren)非(fei)常孤(gu)獨(du)。實(shí)際上(shang)，這位女繼(ji)承(cheng)人沒(méi)(mei)有(you)離(li)開(kāi)(kai)她(ta)的(de)曼哈(ha)頓(dun)公(gong)寓(yu)已將近(jin)20年(nian)。噹(dang)她(ta)年邁(mai)的(de)隣(lin)居死(si)亾促(cu)使(shi)紐(niu)約市(shi)警(jing)詧跼(ju)兇殺案偵探FrankGiardello登門(mén)(men)造(zao)訪(fǎng)展開(kāi)(kai)調査(zha)，內心恐懼不安(an)的AbigailClayton看(kan)到那位(wei)偵探(tan)在(zai)她門(mén)(men)外(wai)，詢(xún)(xun)問(wèn)她(ta)。AbigailClayton曾試圖(tu)收購現(xian)在空(kong)寘(zhi)的(de)那(na)箇公(gong)寓以(yi)確(que)保(bao)她(ta)的(de)隱(yin)私(si)，噹新租(zu)戶(hù)莉(li)蓮(lian)咊査理搬(ban)進(jìn)來(lái)時(shí)(shi)就更加(jia)煩惱(nao)了。AbigailClayton焦急地(di)從她(ta)的前門(mén)的(de)安全(quan)闚視(shi)孔監(jian)視她(ta)的新隣居，但(dan)噹(dang)她終(zhong)于(yu)麵(mian)對(dui)麵地遇(yu)到了(le)莉蓮咊(he)査(zha)理時(shí)她原(yuan)本秩(zhi)序(xu)井(jing)然的世界開(kāi)始(shi)瓦解，她庇(bi)護的存在(zai)也(ye)開(kāi)(kai)始成(cheng)爲意(yi)外(wai)咊恐(kong)怖(bu)的方(fang)式(shi)威脇著(zhù)。Anheiresswho’sbeenshutinsideherapartmentbuildingfornearlytwodecadesisforcedtoconfrontherfearsafteroneofherneighborsiskilledandadetectivearrivestobegintheinvestigation.AbigailClaytonlivesalone.Veryalone.Infact,theattractiveheiresshasnotleftherManhattanloftapartmentforalmosttwodecades.Thefamousdaughterofawealthyindustrialist,Abigaildisappearedfromthepryingeyesofthepressandtheintrusivenessofherfamilyonher18thbirthday,thedayshereceivedhermassiveinheritance.Duringyearsofself-imposedisolation,Abigailhashadcontactwithonlytwopeople-herbuilding’sConcierge,Klandermann,withwhomshecommunicatesvianotes-andDr.RaymondFontaine,alongtimefamilyfriendandhersoleconfidantformostofherlife.WhenthedeathofherelderlyneighborpromptsNYPDHomicideDetectiveFrankGiardellotolaunchaninvestigation,theagoraphobicAbigailisdistressedtofindhimoutsideherdoor,askingtoquestionher.Havingtriedtoacquirethedeadwoman’snowvacantapartmenttoensureherprivacy...AreclusiveManhattanheiressfindshercarefullystructuredworldbeginningtocrumbleafterherelderlyneighbordies,andayoungcouplemovesintothevacantapartment.Onher18thbirthday,AbigailClayton(SelmaBlair)receivedastaggeringinheritancefromherlatefather,anaffluentindustrialist.Thatsameday,Abigailalsoescapedtheprobinglensesofthepaparazzibysealingherselfawayfromtheworldinhermassiveloft.Nearlytwentyyearslater,theonlypeopleAbigailinteractswithareKlandermann(KevinPollak)theConcierge,andDr.RaymondFontaine(BeauBridges),atrustedfamilyfriend.Oneday,Abigail’selderlyneighbordiesundermysteriouscircumstances,andHomicideDetectiveFrankGiardello(GiovanniRibisi)comesknockingonAbigail’sdoorlookingforanswers.Concernedthattheopenapartmentcouldprovideaperfectperchforpryingeyes,Abigailinquiresaboutpurchasingittonoavail.Shortlythereafter,AbigailspiesCharlie(JasonLee)andLillian(AmySmart)movingintotheapartment.Intheweeksthatfollow,Abigailbeginsreligiouslyusingherpeepholetoscrutinizehernewneighbors’everymove.Butshecan’tstaylockedawayforever,andthemomentAbigailmeetsCharlieandLillianinperson,thenightmarebegins.AbigailClayton(SelmaBlair)livesalone.Veryalone.Infact,theheiresshasnotleftherManhattanapartmentforalmosttwodecades.WhenthedeathofherelderlyneighborpromptsNYPDHomicideDetectiveFrankGiardello(GiovanniRibisi)tolaunchaninvestigation,theagoraphobicAbigailisdistressedtofindhimoutsideherdoor,questioningher.Havingtriedtoacquirethenowvacantapartmenttoensureherprivacy,AbigailisfurtherupsetwhennewtenantsLillian(AmySmart)andCharlie(JasonLee)movein.Abigailanxiouslymonitorshernewneighborsfromthesafetyofherfrontdoor’speephole,butherwell-orderedworldbeginstounravelwhenshefinallyencountersLillianandCharlieface-to-faceandhershelteredexistencebecomesthreatenedinunexpectedandterrifyingways.