The ad in the small weekly was seemingly innocent and poignant: "For Sale: Wedding dress. Size 10. Never used." But why, asked the editor of the Van Brunt Citizen, would a childless middle-aged couple, newcomers to Westchester County, have a wedding dress to sell? His question finds its mark in New York State Police Inspector Merton L. Heimrich, who can never let riddles go unchallenged.

Heimrich's first stop on the way to the answer is the accidental death, a year before, of the couple's daughter. But was it an accident, or did someone make the horse shy and throw the girl into the stone wall? Heimrich can't be sure, and his questions multiply when he runs smack-dab into a suicide (?) and a sniper waiting for another girl on a lonely, rain-swept road.