A truly intriguing setup to a new world with a fresh cast of characters and their problems.
Luke has spent his last few years miserable, first waking up as a medical experiment, then being forced to be a side show attraction. He doesn't see any hope in the world but when the chance to run comes in the form of a wolf he takes it, hoping there can still be something more in this life. Red is running on a single minded determinedness to find his sister and protect her as like their pack was supposed to. Finding a merman, this non-human non-wolf person, is just a step towards getting what is most important, and he doesn't care about what actually happens to Luke. But as the two begin to find themselves intertwined it turns out they could have more together than they knew.
It wasn't entirely clear in this book if shifters are known of or not. Luke was a side show attraction as a merman, so that does seem to say that people somewhat know of shifters. Also, Luke wasn't surprised about finding out that Red was a wolf shifter. But at the same time it seemed to be that wolves live in packs hiding from human society and only occasionally interact with them, so again, not entirely clear if humanity as a whole know s about shifters. One thing that is made clear is that people in power know about shifters and they want humans to have the power that wolves have. That has lead to horrible experiments, one of which Luke found himself a part of, forever changing his life.
The disconnect between Luke and Red is interesting. It is based on what they are and what they aren't. Since Red was born a wolf he feels most connection to other wolves, and even then the most connection to born wolves. Born wolves are different than changed wolves because humanity is different and Red see those differences. With Luke being a changed human but also not a wolf, Red is very uncertain around him at first. He tells himself that he feels no connection, but the fact that his wolf could immediately identify Luke as a non-wolf, but also as something akin, shows that there was something there that Red was trying to deny.
The situation with the safety here is quite intriguing. In a world where those in power are using shifters for experiments to further their own power it would be difficult to hide. Not to mention that to find the money to hide would be even worse. So the way that they do it is a fascinating twist, and one that could have ramifications in further books along. It will be interesting to see what happens with these new wolves and what will become of the shifters in this changing world.