Kit Livingstone has been bequeathed by his great grandfather Cosimo an apparently impossible task: to piece together a 17th-century map whose fragments are scattered not just throughout this universe but other universes too. Aided by his girlfriend Mina herself in Hapsburg-Empire Prague Kit begins to make progress but realises that opponents in the shape of the Burley Men are equally determined to capture the map & they have a crucial advantage: the ability to manipulate the will of historical figures for their own ends.