Ramez Naam's Apex is the last part of the Nexus trilogy, following the novels Nexus and Crux. It doesn't do well as a stand-alone, so if you're going to dive into this - and you should! - then you ought to go back and start at the beginning.
But if you've been through the first two volumes? I'm pretty sure you're hungry to see what comes next. In fact, you've probably read it already, because I was somewhat delayed, and it's been out for days.
Nexus is - oh, it's a drug. But then it's also technology. It can be a permanent installation in the human brain, enabling direct mind-to-mind contact. Group thinking. Indeed, hiveminds. It can change the world for alzheimer's patients or people with autism. It can accomodate all the greatest human virtues; not only make people smarter, but kinder, more compassionate.
But nexus is not, in this world, legal. As with any illegal substance, it's all too easy for malicious agents to corrupt the product, without immediate repercussions. Diluted drugs are bad enough - the tech in your brain? It can be hacked.
Meanwhile, the world is hunting you, jailing you, punishing you, no matter what your reasons for employing nexus might be. You're a criminal. You are, in fact, posthuman. And posthumans? They don't have, well, human rights.
A character tries to reason with a politician, talking about homo sapiens and neanderthals and how it all turned out okay in the end, forgetting how even a neanderthal would likely frown mightily at you if you'd outlined the future of his species for him.
But nexus is just one of the new gamechangers, of course. How about a successfully uploaded, digital human mind?
(Successful? What does that mean, anyway?)
An army of thoroughly physically enhanced clones?
How about the bunch of kids who created the strain of nexus with only the best of intentions - the ones partying inside each other's minds, dreaming of the better future, not at all prepared for violent political reactions; torture, concentration camps, a whole new war on terror-
Apex is a great ending to a great trilogy, and I've been very happy to read all of it. The books are dense with the kind of stuff that puts me into a lasting "Oh, cool!"-mode. I only wish the characters, overall, were a little more clearly drawn, a little deeper. I don't mean they're inadequate, exactly, I even cried a little when I thought my favourite(!) dropped out of the story, but... but I didn't get to feel attached to many of the POVs, and that can be a little problematic through several hundred pages.
It's not a big enough problem that I'd hesitate even a moment to recommend these books to people interested in science fiction where the focus is solidly on technology's effect on society (psychological, political, philosophical!). Really. I think these books present a great list of questions to consider - perhaps some of the issues discussed are not entirely immediate-near-future, but some of them certainly are. Naam has included afterwords for each of the novels in which he points to real, current technology reflected in the books, which is awesome. He's also written a couple of non-fiction books about the same topics, both of which I'm definitely interested in reading! ( More than human: Embracing the promise of biological enhancement truly is the most tempting title I've seen in a while...!)
Oh- there was a twitter hashtag too, asking "With nexus, whose mind would you most like to link to?" - Which is a tough one. I think I'd like to shake mind-hands with a theoretical mathematician. It'd be the best kind of thrill to suddenly be inside of that particular skillset. Or knowledge base, or, uh, whatever. I would definitely choose that. Meanwhile, though, without nexus or its equivalent, I'll just congratulate myself on still being able to work out stuff like "eight times seven?!" without a calculator. Yeah. Great job. (Hey, when I say theoretical mathematician? Maybe I mean chaos theory. Maybe I mean Dr Ian Malcolm. Maybe I mean a velociraptor.)