In Powder River, Wyoming, Sheriff Marshall is investigating the mysterious murder/suicide an ex-cavalry soldier and his homesteader wife. Meanwhile, Eli waits for Cornelia's return on the Clarkes' farm, but discovers a more sinister side to their business.

Fifteen years earlier, on Wyoming's Chalk River in 1875, Thomas Trafford arrives to establish his cattle ranch, along with his accountant and aide, David Melmont. But events take a sour turn when Melmont becomes involved in a horrific crime, which ultimately has an immense impact on the lives of both Eli and Cornelia.

As Eli aims to make penance for his actions 15 years ago, Trafford desperately tries to feed his herd with an immense hayrick, Marshall continues to deal with the fallout of Flynn's death and a fresh attack on Trafford's cattle, and Cornelia has a run-in with the businesswoman Black-Eyed Mog.

As Eli and Cornelia reach Powder River, a violent attack on his hayrick forces Trafford to make a difficult decision, and Marshall discovers the truth behind the branding. When Melmont finally returns to Wyoming, the stage is set for a violent confrontation.