This book was:

1. Boring!! It dragged so much, and I almost DNF’ it several times. The only scary scene was the one where Heather went in the submersible to the challenger deep (but she was ranting and proving the world right the whole way).
2. Really badly written. Oh lord the writing was repetitive and infuriating.
3. Had only awful characters that I didn’t care about what happened to.
4. Was really preachy and condescending. Every time the Toth character opened her mouth it was annoying.
5. The science was so stupid, and the whole mermaid/siren thing was not believable at all. Like the pressure problem isn’t really answered, how could the mermaids go from 11 000 meters below surface to above the surface?? No other living creature on earth can do that, with good reason. I wouldn’t have minded if it was a fantasy book, but since it’s supposed to be science fiction, you better make me it somewhat plausible.
6. There were so many writing errors!!! Tory apparently held her breath for at least an hour. The doctors called Jason’s death to 11.22 pm, when it apparently was at night AFTER midnight (unless a whole day went by without the author telling us about it). Heather was at least 8000 meters below surface, but in the next instance, she’s 200 meters below surface. The matriarch couldn’t stand light, but in the beginning of the book the mermaids are attacking in broad daylight.

I did not like this book.

I wanted to get into it. But I couldn’t. Long, unnecessary descriptions about everything, whether minor or significant. 50 pages and hardly anything happened. We already know it’s mermaids. Not worth my time.