The Dawn of a To-morrow - Frances Hodgson Burnett

A wealthy London business man takes a room in a poor part of the city.He is depressed and has decided to take his life by going the next day to purchase a hand gun he had seen in a pawnshop window. The morning comes with one of those 'memorable fogs' and the adventure he has in it alters his decisions and ultimately his life. (Summary by Linda Andrus)