Theories of Flight — Simon Morden

Theorem: Petrovitch has a lot of secrets.

Proof: Secrets like how to make anti-gravity for one. For another, he's keeping a sentient computer program on a secret server farm - the same program that nearly destroyed the Metrozone a few months back.

Theorem: The city is broken.

Proof: The people of the OutZone want what citizens of the Metrozone have. And then burn it to the ground. Now, with the heart of the city destroyed by the New Machine Jihad, the Outies finally see their chance.

Theorem: These events are not unconnected.

Proof: Someone is trying to kill Petrovitch and they're willing to sink the whole city to do it.