It's Christmas in Posadas County. Undersheriff Estelle Reyes-Guzman is settling down to a quiet evening with her family until her doctor husband receives a call from the retired chief-of-police, Eduardo, who is at a nearby hotel having pains. Estelle then receives a call that the retired man had an exchange with two men and then collapsed. The men took off in Eduardo's car. An out-of-town couple, the woman on the verge of giving birth, were the only witnesses to the encounter, but something in their story seems off.