As you're already playing Aberrant, I'd recommend The Directive.
It's the reference sourcebook for Aberrant on their S.H.I.E.L.D. type agency, and gets dark and dirty in the shadows. The official word when it was created was that there was "a mutual need to monitor the international climate of the Nova Age." Sound ominous enough for you?
This answer is going to be part personal experience, and part review, but the TL;DR summary: It's a book on espionage in the Nova Age, and a lot of background and crunch to back it up. I've used it with great success in an Aberrant game, and wholly recommend it.
The book exists in a strange place in the Aberrant timeline, having been released right before Phase I was introduced- it was the first book in the new time-forwarded phase, and the layout feels like an almagam of those two periods.
The first half of the book is all background and information on the Directive's relationship with the rest of the world, and has some good generic intelligence info, procedures, and terminology. There's no crunch in that area, and because of the layout it can be difficult to read. But there's a wealth of information there.
The second half gets into the systems, with new Backgrounds, Abilities, and gadgets, before getting to the new systems, i.e. creating characters in the Directive. There's a great section on torture and telepathy, privacy laws, bugs and other intelligence gathering devices, and more.
Then it gets into the why... why run a game with the directive? What are some directions you can take with it, and what are some story ideas?
Finally, you have the stat blocks on some of the important personnel. Pretty standard stuff, though there's a few gems within this part, also.
Back in 2000, I ran a game Dark Aberrant. It was a combination of Cyberpunk and Aberrant, set in a dark future, and the players were affiliated with Project Utopia. Utopia was rotten at the core, and at that core lay a lot of what I used in The Directive. The background and additions in the book directly added to the ability to run the game with a dark spin and shadowy plots and goals. The information on how intelligence worked in a world with Novas was a big help, and the ideas spun up plots that I'd not have thought of otherwise.