Heresy - Anselm Audley

On the storm-wracked waterworld of Aquasilva, supreme religious power is held by the Domain, dedicated to Ranthas, the God of Fire. But there remain followers of the elements of Water, Earth and Air - living in fear of the fanatical warrior priests of the Domain. Standing between these persecuted few and a new age of religious fundamentalism are Cathan - son of the Count of Lepidor - who is travelling to inform his father of the discovery of a cache of iron in their territory, and a small group of allies.
All across Aquasilva, change is being battled and ruthlessly suppressed by the Domain and its holy warriors, the Sacri. A weapon must be forged to fight them, and Cathan discovers at first hand how long and difficult that struggle will be . . .