The Secret History Book 4: The Keys Of Saint Peter

16th century Italy. The internecine struggle of the Archons has ended in the destruction of the Hohenstaufen dynasty. Yesterday's alliances are no more, and each house pursues its own purposes. With the aid of Nostradamus, Aker investigates phenomena that can be caused by nothing other than the use of runestones of power comparable to hers and her siblings' - icons of power that none of them created, and none of them seem able to control, but instead come from some other power entirely...