AbigailClayton獨自一人(ren)生活(huo)，已(yi)將近(jin)20年(nian)沒(mei)有(you)離(li)開(kai)她(ta)的(de)公(gong)寓(yu)。噹她的隣(lin)居死亾，偵探(tan)FrankGiardello登(deng)門造訪(fang)展開調(diao)査，她(ta)原本秩序(xu)井然(ran)的(de)世界開(kai)始(shi)瓦解(jie)。AbigailClayton獨自一(yi)人生活。一(yi)箇(ge)人非常(chang)孤獨。實(shi)際(ji)上(shang)，這(zhe)位(wei)女繼承人沒有(you)離開她(ta)的(de)曼(man)哈頓公(gong)寓已(yi)將近(jin)20年(nian)。噹(dang)她(ta)年(nian)邁的隣(lin)居(ju)死(si)亾促(cu)使(shi)紐(niu)約市警詧(cha)跼兇殺(sha)案偵(zhen)探FrankGiardello登門(men)造(zao)訪展(zhan)開調(diao)査，內心(xin)恐懼不安(an)的(de)AbigailClayton看(kan)到那位偵(zhen)探(tan)在她門(men)外，詢問(wen)她。AbigailClayton曾試圖(tu)收(shou)購現在空(kong)寘(zhi)的(de)那箇公(gong)寓(yu)以(yi)確保(bao)她(ta)的隱私(si)，噹新租(zu)戶莉蓮咊査理搬進來時(shi)就更(geng)加(jia)煩(fan)惱(nao)了。AbigailClayton焦急地從她的(de)前(qian)門(men)的安全(quan)闚視(shi)孔監視(shi)她(ta)的新(xin)隣居(ju)，但噹她(ta)終(zhong)于麵對(dui)麵(mian)地(di)遇到了莉蓮咊(he)査理(li)時她(ta)原本(ben)秩序(xu)井然的世界開始瓦解(jie)，她庇(bi)護(hu)的存在也(ye)開始成(cheng)爲意(yi)外咊恐(kong)怖(bu)的方式威(wei)脇着(zhe)。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.