(Disclaimer: English is my second language, so I want to apologize in advance for there may be mistakes in the text below. If you find any, please let me know so that I can correct it. I'd really appreciate it. Thanks.)
Review Soundtrack: I suggest reading this review while listening to Burning Down The House, by Talking Heads (Spotify, YouTube).
There are books that grab you from the very first sentence. And there are books that you can't get into, not matter how hard you try like them. Unfortunately, Flex, Ferrett Steinmetz's debut novel, is an example of the latter, despite its interesting premise.
In the world of Flex, magic can be distilled into crystal form. The "flex" of the title is a drug that allows its users to modify reality and create unlikely events at their will. In fact, magic comes from the obsessions of extremely dedicated 'mancers, and can take the most strange forms: bureaucromancy, videogamemancy, paleomancy... The problem is that the practice of magic comes with a price: the "flux", concentrated bad luck, the way the universe has of balancing the odds.
I quite like this idea of magic as a localized decrease of entropy that somehow affects reality and has to be compensated by paying a toll. Also, the different types of magic, that come from obsessed individuals trying to impose extreme order with mundane activities, are very interesting even if they are not exactly original (I am thinking, for instance, of the Marla Mason series by Tim Pratt, with its pornomancers, technomancers and biomancers).
My problem with the novel is that all these promising ideas are not fully exploited. In fact, I'd dare to say that they are barely explored and, what is worse, the possibilities of magic are never clear to the reader. Thus, we have Sanderson's First Law of magic in action here: "An author's ability to solve conflict with magic is directly proportional to how well the reader understands said magic". In Flex, we never know what is within the true capabilities of the 'mancers and what are their limitations. As a consequence, everything magical related seems... random. It works one way, but it could perfectly well work in a completely different fashion.
The actions and motivations of the characters also seemed arbitrary to me. For instance, Paul Tsabo, the main protagonist, discovers to his surprise that he is a 'mancer, but he later behaves as he has been practicing magic for all his life. Anathema, his antagonist, is not better: she acts erratically and when, by the end of the book, her real goals are revealed, I could not help feeling very underwhelmed by their sheer ludicrousness.
The prose didn't work for me either. The style is direct, with short sentences and very few descriptions. When correctly used, this kind of writing can be very effective, but in this case I think it failed to convey the true essence of the world to the reader. All in the novel seems vague, blurred and lacks definition. I am not the kind of person that usually enjoys long descriptions, but in Flex I missed more in-depth depictions of the characters, the settings, the world as a whole. Regarding the dialog, I guess it is supposed to be witty and humorous, but in my opinion it was just superficial and slightly annoying. Also, the continuous repetition of certain terms (such a 'mancy) can be really tiresome after a few pages.
All in all, I was quite disappointed by what I found in Flex, a novel that I was really looking forward to read. Your mileage may vary, of course, but I can't really recommend this one. For me, it was ultimately more flux than flex.