The tides of destiny have bound the Prince of Salt and Sea to a mortal bride—if she dies, his kingdom burns. Ronan, Prince of the Selkies, would sacrifice anything for his people. When a vision from the sea goddess Thalassa reveals that his fate—and the survival of his realm—is tied to a mortal princess, he has no choice but to claim her as his bride. Emma has always been the overlooked youngest princess, eager to carve out a sliver of freedom for herself. So, when a selkie prince arrives, demanding she abandon the life she’s fought for, she refuses to be a pawn in Ronan's game. But danger lurks in the glittering shadows of the selkie court, where enemies whisper and alliances are as shifting with the tide. With conspirators plotting against them and an undeniable tension sparking between them, Ronan and Emma must decide what love and freedom truly mean—before they lose each other, and their kingdoms, forever.