St. Paul, Minnesota. October 1, 1917. High above the city, a renowned local financier named Artemis Dodge lies facedown on the floor of his armored penthouse sanctuary, a single bullet hole in his head. Thirty stories up, in the city's tallest building, and not a shred of evidence or sign pointing to anyone having broken into the wealthy man's fortress. It is -- to all appearances -- an impossible crime. Enter Shadwell Rafferty: Irishman, St. Paul...