Nexus, Crux and Apex, by Ramez Naam

These three novels are among the most interesting science fiction novels I have come across in some time..Lovingly detailed descriptions of the brain-nanoparticle operating system (Nexus) that allow people to hack their own brains, regulating mood, compelling actions and desires and enabling communication mind-to-mind seem plausible (after you swallow the sufficiently-advanced-technology bits) enough to support a tale of personal discovery by the author of the OS as he winds between the US government, Chinese spies, Thai drug lords and showdowns with the US government and a singularity’s intelligence. A good actioner, the story will compel your attention through all three books and make you wish for a different ending to the last one, for sure.

Highly recommended.  The links above go to Amazon, but are available at sfpl.org.