Langdon and Katherine descend a spiral ramp deeper into Threshold, disappointed to be moving farther underground but intent on escaping with the evidence they have gathered. Above them, rapid hard-soled footsteps follow, convincing them the person behind them is no harmless staffer.

They pass into a short, dim, matte-black corridor and glimpse a caged room of computer racks pulsing with lights, which Katherine identifies as quantum machines protected by Faraday shielding. Neither of them considers entering the caged area, fearing it would become a trap.

Turning into a longer corridor, they spot a stairway symbol at the far end—an apparent route back up—but realize they cannot reach it without being seen. Two doors offer poor options: a "SUPPLY ROOM" that looks like a dead end, and a larger recessed door protected by an RFID scanner they can no longer use.

Langdon abruptly opens the supply room and bowls a bottle of cleaner down an aisle, triggering motion lights deep inside. He then closes the door but leaves it cracked so a thin wedge of fluorescent light spills into the hall, and he pulls Katherine toward the stairs.

Before they reach the stairwell, Langdon veers into the shallow recess by the RFID-secured door. Pressed against the metal, they try to vanish in the alcove as the footsteps enter and stop; after a tense silence, Katherine hears a gun being cocked. The scene then cuts to Jonas Faukman waking at his desk to the sound of rain, feeling dread return, and repeating a cryptic reassurance—"RL&KSRGUD."