Serendipity loves horses. No-one in Lahn Dan has ever seen one, apparently they died out before the Gases - but there are statues of them around the city, paintings and drawings too if you know where to look. And there's the little lost wooden horse Mama gave Serendipity when she was little. When Mama dies, Seren is taken under the wing of Professor Nimbus, a storyteller. Nimbus is kind and knowledgable, but Seren has started to question the Minister's rule and life beyond the high, impenetrable Emm Twenty-Five wall. Hidden among Mama's few possessions was a map which suggests there is life outside of Lahn Dahn, and a place where horses live and roam freely - out beyond the wall and the Minister's grip. So, with the help of a trader boy called Tab and his little dog Mouse, Serendipity heads into the unknown, searching for the beautiful creatures she's always dreamed of.