Spira Mirabilis (The Wave Trilogy)

In the 1347th year of Our Lady the engineers of Concord defeated the fractious city-state of Rasenna using the magical science of Wave Technology. The City of Towers fought back, and for a while Concord's plans for domination were halted. But First Apprentice Torbidda regrouped, and reformed Concord to his own design. Now he is in absolute control, and plotting the final battle that will pacify Etruria... permanently. Contessa Sofia Scaligeri could rally her people once again, but she is far away in the Crusader Kingdom of Akka, trapped with her son by the tyrant Queen Catrina. Darkness is falling. The final battle must be fought and the tide must be turned, lest evil reign forever.