A red tide is rising.
Jade, a seventeen-year-old mermaid in the underwater city of Thessalonike, finds her world upended when her fiance murders a naiad.
As tensions surge between the mer and the naiads, Jade must navigate murky waters, negotiating her responsibilities as the daughter of one of the king’s most trusted advisers and her budding friendship with a naiad.
But as she tries to fight the tide of anger in a city that lives for scandal, she discovers that danger lurks in every canal. If she fails to mend the divisions between their worlds, the up-welling of hate will threaten to rip apart everything she loves.