Nothingismorefrightening,asthenarratorpointsout,thana‘time-richnosyperson’.ExhibitAisAhnGeo-ul(GyeongSu-jin),whocommitsherselftosocialjusticecauseswithterrifyingtenacity.AftertemporarilyrentingaunitintheBaek-saeApartmentbuilding,shediscoversthataloud,hardtolocatebangingnoiseoccursfrom4ameverynight,makingtheresidents’livesaninsomniachell–andsoshedeterminestoengageinherowndisruptionandtofindtheculpritofthisacousticassault,simultaneouslyeliminatinghereccentricneighboursassuspects,andrecruitingthemtohercause.　　Focusingonawomanwhoisanunstoppableforceforgood,itisalsoapleaforcommunitycohesionandsolidarity.