When Merlin is weighed down by sorrows, Jack and Annie travel back to feudal Japan to learn one of the four secrets of happiness.

She has only seen the world through maps. She had no idea they were so dangerous. Boston, 1891. Sophia Tims comes from a family of explorers and cartologers who, for generations, have been traveling and mapping the New World -- a world changed by the Great Disruption of 1799, when all the continents were flung into different time periods. Eight years ago, her parents left her with her uncle Shadrack, the foremost cartologer in Boston, and went on...