Having slipped through a jammed door and locked it behind them, Robert Langdon quickly realizes the small, carpeted antechamber they entered does not lead to safety. The pale-blue tunnel lights are already on, the passage slopes downward, and RFID access suggests they are heading deeper into Threshold’s most secure interior rather than toward an exit. Langdon briefly considers surrender, but fears the relentless pursuer may be Mr. Finch, who will do anything to protect Threshold.

Langdon and Katherine Solomon move down the curving tunnel to a second arched entrance framed in black stone and sealed by a frosted-glass door etched with a familiar symbol. Both sense that everything they have seen so far—robotic surgery, VR systems, artificial neurons, and brain chips—may have been only a prelude to what is beyond this door.

Langdon cracks the door and is startled to find himself looking up into a high domed ceiling. The chamber is a vast, perfectly round space that Langdon recognizes as the Folimanka Bunker’s deepest “blast shelter,” repurposed into something unrecognizable and far more advanced.

Inside, they see a central raised circular platform with at least twenty outward-facing cockpit-like workstations. Radiating across the plush carpeted floor is a precise array of sleek metallic pods—minimalist, torpedo-shaped shells aligned with each workstation like spokes on a wheel.

Investigating one pod, Langdon presses a recessed button and a tinted glass lid opens with a hiss, revealing a padded interior with restraints and an IV connector. Katherine recognizes it as an advanced successor to the suspended-animation pod from Gessner’s lab, now fitted with a specialized head cradle designed for wireless interfacing with brain implants. As the implications click into place—altered states of consciousness pushed to the ultimate boundary—Katherine takes Langdon’s hand and names what they have found: Threshold has built a “death lab.”