In the course of solving recent murders, Dunbar relates the death of an earlier victim of the same perpetrator.
Dunbar comes to the Hook Ranch near the town of Eminence and goes to work as a ranch hand. The narrator, Edwin Ryerson, or Rye, has a niece named Vivian, who works at the mercantile in town. As the story gets under way, one of the ranch hands comes to Rye and tells Rye that he hopes to propose to Vivian and to give her a diamond. Before long, the vapid young suitor turns up dead. The story becomes more complicated with more victims.
Rye accompanies Dunbar to places such as the mercantile where Vivian works, the restaurant where Vivian goes to work next, the Double Eagle Saloon, and a brothel named the Blue Diamond. The search for truth takes them into the tawdry world of a former street woman who is raising the orphaned child of a street woman who was murdered in Ogallala.
This story also features Medora Deville, a lady friend of Dunbar who has appeared in other Dunbar stories. In this story, she opens a restaurant where Vivian and the former street woman go to work.
In the final segment, Rye and Dunbar go to the Blue Diamond a second time and pursue the main suspect in the snow in order to try to bring him to earth.