Puzzles involve an 1886 Coca-Cola trade card, a map connected to a Civil War battle and a billy club from a 1912 textile-factory strike in Lawrence, Mass. Included: a trip to Coca-Cola headquarters in Atlanta to try to verify the trade card info; digging up details pertaining to the 1863 siege of Vicksburg, Miss.; a journey to Lawrence to investigate the Bread and Roses strike.