As the old saying goes, "You can pick your friends, but not your relatives." In tranquil Northumberland County, Ontario, two families are well acquainted with the grim truth of that innocuous-sounding expression. They are the descendants of the first, and only, man executed in Northumberland's history. In a sordid true-crime tale of poison and philandering in 1850s Ontario, the respected Dr. William Henry King astonished the countryside with the sinister...