Now, let's talk about the romance. I'm really not entirely sure how I feel about it. On the surface (water pun!), Lily and Calder's relationship falls into the typical YA paranormal relationship: dangerous paranormal boy and the girl who cannot resist him because he's oh so pretty. Not to mention the fact that I was a little uncomfortable with how young Lily seemed, especially when paired with the fact that Calder is who knows how old and a killer merman.
However, there was another side to their romance that was a bit more unique that makes me somewhat okay with it. Lily, though she is attracted to Calder, does not immediately give into that. She hides it successfully for a while. It takes her some time to trust him. She confronts him openly and repeatedly about what his deal is and why he's following her around. That, I liked. In the end, though, she still goes for him, and isn't particularly angry to learn that he's lied to her or tried to kill her dad. Considering that she loves her family, her reaction was completely unbelievable.
The real problem I had with Lies Beneath, though, was the world building. Basically, I cannot fathom (another water pun!) how mermaid respiration works. I can totally accept that they shift into their mermaid forms. When human, they breathe like people do; as mermaids, they can breath underwater. What I don't get is why they can breathe underwater AND above the water in their mermaid forms.
Fish breathe via their gills. Do the mermaids have gills on their tails? That would explain why they can breathe with their heads out of the water, since the tail would still be submerged. Unfortunately, that does not explain how Calder was able to breathe oxygen into Lily's mouth while they swam around. Even if he does breathe through his human mouth, he wouldn't be exhaling oxygen. Humans don't exhale oxygen and neither do fish. I guess he could be processing the water into oxygen and immediately passing it to her, but I just had trouble with the whole thing.
If you're a reader that is frustrated by little details, like I am, you may want to try another book. However, if you're note, Lies Beneath is a well-written paranormal romance novel.