Poseidon (or Fishtail, they're the same book) is book 2 in the Colony: Aqua series and follows immediately follows the story in Halcyon. The book is written in third person omniscient from both characters' point of view (alternating by chapter). I really enjoyed this book. Just gotta say. It was short and sweet with a solid cast of characters, some of which we met in the last book. I liked Sven's personality, even up to and including his touch of cockiness. Minali's more serious mindset made a good counter to his playful antics. It is a short book, so the romance isn't particularly protracted, but that's to be expected and I feel it still worked very well. The book is about the leader of the Mer colony and a human detective as they work to solve a murder that really wants to point at Sven. The case is a good backdrop for their story, and I'm really interested to hear more of Bolina's story some day. If you like your mermen to be colorful and perky, your sci-fi full of interesting peoples, your romance a bit steamy, and a touch of murder mystery thrown in for good measure, this is a story you should grab!