AmericanpsychologistJohnHoldenarrivesinLondontoparticipateinasymposiumaimingtoexposewitchcraftanddevil-worshipasafraud,withattentioncenteredonacultrunbyaJulianKarswell.Debarkinghisplane,Holdenlearnsthatthesymposiumleader,HenryHarrington,hassuddenlydiedandheisnowincharge.WhatonlytheaudienceknowsisthatHarringtonwasclearlykilledbyademon,apparentlysummonedbyKarswelltoavengehispersecution.DespiteboththreateningandcajolingbehaviorbyKarswell,Holdendeterminestoproceed,thoughtheonlycultmemberwillingtotalkabouthisexperiencesisinaprisonpsychiatricward,catatonicafterallegedlykillingyetanothercultmember.However,Harrington'sniece,Joanna,believes,basedonheruncle'snotes,thatKarswellmayindeedhavesomesatanicpowersderivedfromanancienttomeinanobscurelanguagewhichhehasbeenabletotranslate,andattemptstowarntheskepticHolden.Karswell'smotheralsoattemptstowarnHoldenoff.However,thethingwhichbeginstomostgettoHoldenaretheoccasional,butmounting,sensoryandmentaldisturbanceshebeginsexperiencingafteranencounterwithKarswell,andthediscoverythat,duringthisencounter,KarswellsecretlyslippedaslipofparchmentwithacurseinrunicsymbolsonitintoHolden'sbelongings,aparchmentidenticaltooneHarringtonrecordedhavinghadpassedtohiminasimilarmannershortlybeforehisdeath...[N.B.HoldenatnopointstaysattheKarswellestate]在视听表达上，导演有意弱化戏剧元素。数字修复让历史影像焕发活力，全彩上色增强画面细节，画面呈现拓展表现空间。但技术使用十分克制，整体色调保持历史本色。整体表现注重精神价值。色彩选择体现历史责任感，声音设计追求简约风格。