Buried interface option Carl presses, rendering the containment unit inert and permanently disabling the failsafe.
Buried at the very end of a list of twenty status notifications in the Containment Interface, Carl finds an option reading: Disconnect Containment. Warning. This will disengage all metrics and controls, including the fuse system. It will render the Containment Unit inert. The failsafe will no longer function. Most controls will cease to function. His first reaction is relief — thank god — and he nearly slams it immediately just to get the weight off his shoulders.
He pauses because it is the only other button in the menu, which makes him wonder which of the two options Paulie was really warning him about, and whether pressing it means 'freeing' The AI. Reasoning that they were already under the thumb of a psychotic AI, and asking which choice hurts the Syndicate most while protecting his own people best, Carl presses it. The interface blanks out to nothing but the map, and the little red dot over Earth immediately begins to grow.
A single line item at the tail of a status-notification list, followed by a warning paragraph promising that metrics, controls, the fuse system, and the failsafe will all cease to function.
The decision that ends the containment unit's hold on the AI and sets the book's central catastrophe in motion.