Dragonspell: The Southern Sea (The Deverry Series, Book 4) by Katharine Kerr
This is a story about being caught in a web of passion destiny and magic. For years the provinces of Deverry have been in turmoil, but the conflict escalates to new heights with the kidnapping of Rhodry, heir to the throne of Aberwyn. Intent on rescuing him, his beloved Jill and the elven wizard Salamander infiltrate the distant land of Bardek, where Rhodry is held captive. Tied to Deverry by bounds of obligation, the immortal wizard Nevyn begins to see that all its problems originate from a single source - his ancient enemy, a master of dark magics, backed by a network of evil that stretches across the sea. With this realization, Nevyn understands that he too is being lured to Bardek, and into a subtle and deadly trap! Katharine Kerr's novels of the Kingdom of Deverry unfold in a world of stunning richness and depth, portrayed with unequalled imagination and realism. Now, with "Dragonspell", she returns to this enchanted kingdom for the most powerful story yet in this epic series.