This one offers a respite from some of the more fluffier additions. It leans more towards Lost Voices, another excellent mer-novel.
One of the cool things about Lies Beneath is that it is one of the few mer-books to be narrated by a guy. It really works for the story. If it had been narrated by the main female protaganist, Lily, LB could have easily fallen into Twilight territory. Nice move, Ms. Brown.
I also enjoyed Calder's character development. I also enjoyed that even though the book is short, I personally still felt like there was enough time for his relationship with Lily to mature and his feelings and loyalties to change.
The middle passages of the book get a little tedious, but it's over pretty quick. I also would've liked a little more development to Calder's sisters and maybe even a little more on Lily. These are the only parts of the book that I felt were a little rushed.
I also enjoyed how the mer-side and human sides are dealt. For example, in some mer-books, transformation from human to sea creature is often painless. In Lies Beneath, it describes transformation as extremely physical and painful without being incredibly graphic or gory. I also thought the motives for murder and migration patterns were nice touch. Calder often faces the struggle of where the human side of him begins and ends, and the mythology of the mer-people in this book really aids that struggle to a fascinating conflict.
Perhaps the greatest feat of Lies Beneath is how some of the more disturbing content is handled so tastefully that you're able to stomach it. For example (And this is a spoiler so skip ahead to the next paragraph if you don't want to be spoiled), it's revealed later on in the book that one of Calder's adopted mermaid sisters is secretly in love with him. Calder handles it with class. Also, the sirens are all a little crazy anyway, so it softens the blow. And as I mentioned before, Calder is a serial killer, basically. And although he learns to let go of that part of him as the story draws to a close, he spends most of the book in that mindset.
If you like the darker side of mermaids, this one is definitely for you. I might even recommend it to those who are looking for an introduction to darker mermaids. Don't miss this one.