Degrees Of Freedom: Metrozone Book 3 by Simon Morden
The Six Degrees of Samuel Petrovitch:
* Michael is an AI of incalculable complexity trapped under the remains of Oshicora Tower. Petrovitch will free him one day; he just has to trust Michael will still be sane by the time he does.
* Maddy and Petrovitch have trust issues. But Petrovitch is pretty sure she loves him.
* Sonja Oshicora loves Petrovitch too. But she's playing a complicated game and it's not clear that she means to save him from what's coming.
* The CIA wants to save the world. Well, just America, but they'll call it what they like.
* The New Machine Jihad is calling. But Petrovitch killed it. Didn't he?
* And the Armageddonists tried to kill pretty much everyone by blowing the world up. Now, they want to do it again.
Once again, all roads lead back to Petrovitch. Everyone wants something from him, but all he wants is to be free . . .