On it's own the Keely Thomson saga is quite good with an engaging, well written heroine and a great premise, and this could have been one of the strongest books in the series, as it introduces some great new elements and wrinkles to the story. Unfortunately, it's not as good as it should have been and this book would have been rated much, much higher if it weren't for the fact that the author continues to make the very poor decision to force the readers to read his "Other Places" series in order to follow all the plot threads in this one. That problem has presented itself before in this series, but it's now been compounded by the fact that Other Places has deteriorated dramatically from an interesting, if somewhat smutty, bit of fiction in volume one to an incoherent and plot hole filled exercise in teenage rape/murder/cannibalism fantasies by volume three, and a large part of the rampant misogyny and torture-porn is inexplicably, and against all story logic, aimed primarily at the 16 year old heroine of this one.
And that's really a shame, as up until Keely 4 (and, to a lesser extent, O.P. 2,) this would have been a series of books that I could have recommended for more mature older teens and up, but the discordant and frequently out of character elements introduced in the later Zach story lines really end up tainting the whole rather badly. In the end it's written at a juvenile level, but it's clearly not for kids. If you don't mind some unexplained story elements, I'd suggest simply skipping the Other Places books and then just reading the five Keelys and the companion book Friend-zoned.