I remember being floored when I first read a short story of hers, Haunted, which was featured in the defunct 1980's magazine, Omni. It merely depicted a visit to a grocery store and not much else happened. The starkness of her description ... insanely chilling. Was the apocalypse an implied character? Impossible to say.
That story was later collected as the title story in her anthology, Haunted: Tales of the Grotesque