I'm unaware of any other authors who are doing what S. L. Huang has done with her Cas Russell series, but I'd love to read them if they're out there, because she leaves you wanting more. Null Set is definitely a middle book, bridging between Zero Sum Game and the next book, with a cliffhanger ending that for once I do not mind. I also don't mind that I can't think of other books to compare this to—only movies. If you like superhero movies, Chinese martial arts movies, and movies like The Matrix and The Fifth Element, you'll definitely be into this dark, gritty futuristic thriller and its gifted and violent anti-heroine. If you can imagine superheroes on steroids, if you dig movies like John Wick and Fast and Furious, that's when you enter S. L. Huang territory.
Read Zero Sum Game first; it takes a while to remember how the first book made you sympathize with Cas; she's an antihero because she's not very likeable, but you root for her anyway, like her friends do. You get little character studies in the action between the action, but you are dropped full tilt into the current situation. Cas can calculate angles so quickly that she can shoot, sprint, jump and punch her way out of most dangerous situations. She and her pals are on the track of and on the run from the evil future corporation that messes around with people's heads, commits the occasional assassination trying to make the world a better place—their way. Hunters and hunted at the same time, perfect action movie plot.
It's really a gift to be able to put a movie on the page like this, to have just enough depth amidst heart-pounding suspense, enough detail but not drown the reader, enough rush for picky readers to not notice any discrepancies. Huang has taken her film and stunt experience and made it work in novel form. Most attempts at writing for adrenaline junkies fail; these books succeed. I am half "give me the next book now" and half "cliffhanger? Never said this before, but ok, maybe in 6 months to a year my heart can take it."
Highly recommended for action fans and adrenaline junkies.
(I received an advanced electronic copy for review, thanks to Netgalley and the publisher.)