The Intelligence Zone - or IZ - Network is a group of State sympathisers and Iz'kal infiltrators that operate behind the scenes of the Corvo management to destabilise Corvo society and undermine the Megacorps' power.
Founded a century ago by a secret group of Iz'kal immigrants that pretended to defect from the State to establish a fifth column in the core of Corvo society, the IZ quickly contacted State sympathisers in Corvo society, and gradually manoeuvred them into key positions in the Tiantang corporate chain of command. With these pro-State moles infiltrated among the Corvo, the IZ spy ring has worked unhindered and undetected for decades now, although many Corvo officials suspect its existence.
Despite having sabotaged may Corvo settlements and missions, and having provided the State with a steady supply of corporate secrets since its foundation, the IZ Network's treated achievement in fact helped the Corvo, when it used its secret influence to convince both sides to form the Corvo-Iz'kal Military Coalition. All the State espionage going on inside the Coalition is handled by IZ agents, but it could reasonably said that, were it not for the IZ Network, the Ravager would have eliminated both the Corvo and the Iz'kal by now.
The IZ Network remains secret, but the Corvo have spent the last forty years running a constant, recurrent search for State spies among their number. It is a matter of time before they discover a clue that will finally lead them to the IZ. When that happens, there will a lot of work - and a lot of money to be made - for a lot of mercenaries, agents, and spies on both sides of the conflict, particularly those operating in Tiantang CS.