It is a five part story about wheat speculation at the Chicago Board of Trade.
As wheat prices fall in the midst of an economic feud between two influential speculators, the story's protagonist, a wheat farmer from Kansas, loses his farm.
The book ends with the farmer relocating to Chicago, where he is denied free bread due to rising wheat prices.
[1] Influenced by naturalism, which the author contrasted with the realism.
The latter he found to be too superficial, honing in on the "accuracy" of surface details, while naturalism he understood to dramatize the "truth" to expose the relations between people from different segments and classes underlying the everyday experiences of life.