The river Irenicon is a feat of Concordian engineering. Blasted through the middle of Rasenna in 1347 using Wave technology, it divided the only city strong enough to defeat the Concordian Empire. But no one could have predicted it would become sentient, and hostile. Sofia Scaligeri, the soon-to-be Contessa of Rasenna, is inheriting a city tearing itself apart from the inside. She can see no way of stopping Rasenna's culture of vendetta...until a Concordian engineer arrives to build a bridge over the Irenicon. He shows her that the feuding factions of Rasenna can continue to fight each other, or they can unite against Concord. And they will need to stand together - for Concord is about to unleash the Wave again...