Sylvester Tilghman is the third in his family to serve as sheriff in the small town of Arahpot, a generally peaceful place as the 19th century winds to a close. His biggest problems are lack of a deputy and the refusal of Lydia, his girlfriend, to marry him despite many proposals.
When Conrad Runkle, a stranger in town, is fatally stabbed, Tilghman recalls Valentine Deibert, an obese man with a wife half his age, had reacted with obvious fear in a recent encounter with the stabbing victim. When questioned, Deibert denies knowing or fearing the victim.
Runkle’s wife arrives in Arahpot and informs Tilghman her husband was in pursuit of a man who had scammed him, bankrupting his business. Suspecting a connection, Sylvester pays another visit to Deibert only to discover him dead of arsenic poisoning. Sylvester is plunged into a flurry of unusual activity and danger. And Lydia is pushing her obnoxious cousin on him as a candidate for deputy. Things continue going from bad to worse until Sylvester finally unravels the mystery.