I haven't read all that many ghost stories in my life, but this has to be one of the best. The atmosphere is so precisely rendered and the thirtyish protagonist is both sympathetic and yet representative of the modern age. An older man would not have worked so well, I think. This man has not been completely corrupted by his life yet.
SMOKE GHOST takes place in a city and you can feel its darkness in every line. Towering, impersonal buildings, dirt, soot, smoke, faceless strangers, physically dark. (Leiber apparently wrote this after moving from Chicago to California).
Mr. Wran, a young businessman, father , husband, begins noticing an odd shape on his way home on the train. Gradually it begins to exhibit a human face and as the story continues, it becomes more and more frightening as it haunts his home, office, and other places he travels to.
Unlike most ghost stories, this ghost does not seem to have come about after a death, but is perhaps composed of the detritus of the city. Maybe even the evil that goes on in those towering towers.
Some incidents from Wran's childhood figure in interestingly, yet I was not sure his ghost emanated from that period. I don't want to say much more because it is better read than described by me.
And it is probably better read twice for novices in the genre.