Ascientistlivinginanapartmentcomplexkillsagirlandusesacidtodestroyherinternalorgansandthenkillshimself.Whileinvestigating,adoctordiscoversthatthescientistwasdoingexperimentsontheuseofgeneticallyengineeredparasitesasorgantransplants.Soonotherpeopleinthecomplexbeginshowingsignsofcarryingtheparasites,spreadingthethingsthroughwantonorgiasticabandon,andthecomplexbeginssufferinganattritionproblem.