MarthaandFélixaretheoffspringofainfamousBelgianserialkillerknownastheButcherofMons,whoterrorizedthenationduringthe1990s.Withafragilepsycheandburdenedbyinsecurities,Marthaseekssolaceintheworldofsocialmedia,livingvicariouslythroughthelivesofothers.Meanwhile,herbrotherFélix,overwhelmedbytheweightoftheirdarkfamilylegacy,takesituponhimselftocontinuetheirfather'sgruesomeacts.AsMarthaenduresrelentlessharassmentandviolentassaultsatherworkplace,heroncedocilenaturegiveswaytomadness.Shefindsherselfcrossingthethresholdintoastrangeandterrifyingrealm,whereherbrotherresides,andthelookingglassmerelyamplifiesthehauntingrealitythatawaitsher.gt