Piper's map showed that the interconnected mainframes that composed the Maas Intertech computer cluster had one serious flaw. R D mainframes were the most vigorously protected, rated at Security Code Red-4. Intrusion Countermeasures guarding the access nodes to these systems would be black, as vicious as IC ever got. The corp knew where its most important assets were located and spared no expense in defending them. The primary security mainframe, however, was merely Code Orange, tough but by no means impenetrable. And the main engineering system, which monitored and controlled the facility's physical devices such as water, light, and heat, was only moderately defended by Code Green security. And that was the cluster's flaw.