Trident of Aurelia

A long-abandoned trident calls out to a drowning woman. As Orianna takes it in her hand, she transforms into a mermaid, and her life changes forever. Hers is a story of ancient sorceries, a cadre of mermaid allies, alien monsters and a massive Leviathan, a story Peter Beagle (The Last Unicorn) calls "enchanting and ominous!"