Book three. Massive spoilers for The Dragons of Dorcastle and The Hidden Masters of Marandur ahead.
It openes with Mari and Alain fleeing Marandur with their loot of volumes. And on the road to the current capital Palandur, because all roads lead to Palandur. More trouble with Mechanics and Mages and Imperials along the way as they start to piece together what they can do with the destiny. There's rumors of the prophecied daughter -- some of which they recognize -- and more rumors about a legendary vampiric empress.
Along the way of their attempts to find the way, there occurs an angry girl who is reconciled by the notion that something is so romantic; a secret tower; confirmation of the first books hints that this is a far-future planet (without explaining away the Mages as science); Alain's asking the significance of certain golden rings; sinking a ship; Alain's successfully passing himself off as a Mechanic (briefly); and more.