After the harrowing events that entangled her in Deadwood, Brigid Reardon just wants to move west and get on with her new life in America. But shortly after traveling to Cheyenne to join her brother Seamus, she finds herself caught up in another deadly mystery—beginning with her discovery of a neighbor's body on the plains near their homes. Was Ella murdered? Are either of the two men in Ella's life responsible? With Seamus away on a cattle drive, her friend Padraic possibly succumbing to a local's charms, and the sheriff seemingly satisfied with Ella's fate, it falls to Brigid to investigate what really happened, which puts her in the crosshairs of one of Cheyenne's cattle barons, called "big sugars" in these parts. All she really wants is something better than a crumbling, soddy homestead on the desolate plains of Wyoming—and maybe, just maybe, she wants Padraic—but life, it seems, has other plans: this young immigrant from Ireland is going to be a detective on the western frontier of 1880s America, even if it kills her.

Loosely based on the true story of Ellen Watson in Cheyenne in 1889, The Big Sugar continues the adventure begun in Mary Logue's celebrated mystery The Streel, which introduced a "gritty, charming, clever protagonist" (Kirkus Reviews).