The island of Eriana Kwai is suffering because the people live off the sea and mermaids have been slaughtering their fishermen and anyone that comes close to the beach. They send a group of men every year called the Massacre to try and cull the mermaid population but after many years of failures, they finally put together that sending men to fight creatures that can easily seduce them is a bad idea. So the solution is send a crew of all women. 
 Meela is one of those women trained to kill and she would be an amazing warrior if she hadn't befriended a mermaid in her childhood that makes her see the enemy as something more than a monster. Her relationship with Lysi, the mermaid, is central to the plot as the book takes you on the first all female Massacre. 
 I enjoyed the diversity of the cast, especially the main character, something not common in YA. The tenderness and confusion of Meela's relationship with Lysi as it matures is definitely the highlight of the book. While the cast of the other girls is confusing and some of them come off as caricatures (Dani) the core of the story is brilliant. While the book has a confusing beginning, it quickly picks up and is one of the most creative and interesting stories I've read in a while.