The Secret of Secrets

Ambassador Nagel helps Langdon and Solomon to sneak out of the residence, following Langdon’s suggestion that they try to break into Threshold and obtain hard evidence. Meanwhile, Finch grows suspicious, and the Golem steals the tool he needs from the Gessner lab, implied to be Gessner’s hand.

As Nagel, Langdon, and Solomon drive toward Threshold, Solomon describes earlier CIA projects involving consciousness, including the real-life ill-fated Cold War-era Stargate project. Solomon grows increasingly annoyed with Langdon’s dismissal of her arguments about non-local consciousness.

Nagel learns that a letter addressed to her was found on Harris’s body, and feels she must return to the embassy. She leaves her car with Langdon and Solomon. Langdon gives Nagel an encoded message to pass on to Faukman as proof of life.

Solomon suggests that Threshold is likely related to her work on remote viewing, in which a person’s consciousness is projected beyond their body to view and hear activity elsewhere. Solomon suggests that Gessner did not help Vesna out of kindness, but because her epilepsy might make her more successful as a remote viewer. She also suggests that Vesna’s friend Dmitri was not sent home to Russia after being cured, as Gessner claimed.

At the US embassy, Nagel is given the letter left for her by Harris’s killer. The message is so shocking that she asks her personal bodyguard Kerble—the only other person who knows about the letter—to leave her immediately.

Langdon and Solomon approach the entrance to Threshold, a nondescript tunnel in Folimanka Park, which is guarded by only two men. Meanwhile, the Golem stands inside the nerve center of Threshold, overwhelmed by emotion, and feels the Ether approaching.

Faukman’s AI searches fail to uncover any connection between In-Q-Tel’s investments and Solomon’s research. He receives an email from Ambassador Nagel with an encoded message from Langdon. Faukman quickly decodes the message, which assures him that Langdon and Solomon are safe.

Langdon and Solomon park in Folimanka Park and hike to the Gessner Institute, which Langdon believes is another entrance to Threshold. Inside, they find that someone has already stolen Gessner’s key card and her thumb, suggesting that the entrance is biometric.

The letter left on Harris’s body directs Nagel to an online video of the Golem torturing Gessner, including a lengthy confession describing project Threshold. Horrified by the details of the project she has been enabling, Nagel places a difficult call. Meanwhile, Vesna wakes, unsure of where she is or how she got there.

The Golem realizes that he has lost his metal wand and falls into an epileptic seizure. Afterwards, he enters the secret passageway from the Gessner Lab to Threshold, searching for ways to destroy Threshold from the inside.

Solomon theorizes that Gessner might have installed an e-card on her phone in case she lost the physical card. She uses Gessner’s fingerprints and face to access the card, but it only lasts for 10 seconds. Unwilling to further maim Gessner or move her body, Langdon successfully sprints to the elevator within the 10 seconds to activate it.

Nagel forwards the Golem’s video to CIA Director Gregory Judd along with a list of demands. She warns that if anything happens to her, the videos will be published. After hanging up, she gives a copy of the video in a sealed envelope to her security guard. Nagel summons Daněk for help finding Vesna.

Langdon and Solomon reach the lower level, a transportation station with open-air trams that transports them automatically to the entrance to Threshold, which is marked with the Vel spear symbol on Gessner’s key. Inside, they find offices and a small hospital, including recovery rooms and an ominous-looking machine.

En route to the ambassador’s residence, Finch receives a call from CIA Director Judd regarding Nagel’s video and demands. Judd warns Finch not to let the situation spiral out of control. Although he believes Nagel is bluffing, Finch decides to go straight to the Gessner Institute.

The ominous-looking machine is revealed to be a robot designed for neurosurgery. The discovery of a room full of VR sets and chairs leads Solomon to reveal how she experienced nonlocal consciousness during a VR experiment in college. When they spot IV bags in a connecting room, Solomon insists on finding out what drugs are being used.

In New York, Alex Conan’s AI research suggests that In-Q-Tel might be interested in Solomon’s work on fractals since they’ve heavily invested in fractal technologies. Solomon’s book uses fractals as a metaphor for universal consciousness: in both cases, the individual unit also contains the system as a whole.

The discovery of psychedelic drugs in the VR lab leads Solomon to theorize that the purpose of Threshold is to rewire test subjects’ brains through intense stimulation. She suggests that Vesna would be a perfect subject as an epileptic, and that Vesna’s memory issues might be related to testing with drugs.

CIA Director Judd worries that a news leak about Threshold would start a global arms race. Meanwhile, the Golem arrives at his destination: a silo at the edges of the Threshold facility with a direct opening to Folimanka Park. In New York, Faukman decides that Solomon’s work on fractals is not connected to Q.

Langdon and Solomon find a room for manufacturing microchips, leading Solomon to admit that the last chapter of her book proposed a theoretical chip that could lower GABA levels to allow the brain to engage with the global consciousness. Solomon insists that the chip could not exist without an artificial neuron, which is currently impossible to grow.

Finch arrives at the Gessner lab and panics when he finds Agent Housemore dead. Inside the silo, the Golem finds a superconducting magnetic energy storage machine, which uses liquid hydrogen to keep the system cool. Knowing that the energy contained in the machine powers Threshold, the Golem determines to destroy it, regardless of the risks of explosion.

Langdon discovers a lab, and Solomon finds a protocol book that proves that Threshold has produced artificial neurons. Solomon realizes that the protocol described is exactly the process she proposed in her book, then reveals that she initially proposed the process in her graduate dissertation over two decades earlier.

Solomon recalls how her graduate dissertation was rejected from a prestigious prize for reasons other than merit. She then realizes why the CIA wants her manuscript. Meanwhile, Finch finds a metal wand in the Gessner lab lobby, leading him to believe that either Vesna or Dmitri Sysevich killed Gessner and Housemore, since they are the only two patients with the implant. In the silo, the Golem, closes the emergency vents.

Solomon reveals that after her dissertation was rejected, her professor urged her to submit a patent for the artificial neuron technology. The patent was rejected, and all of Solomon’s copies disappeared. When the professor died, his daughter gave Solomon a copy of the patent, and Solomon had planned to publish it in her book. As they attempt to leave, lights come on in an adjoining room, and they are forced to escape into a hidden doorway.

While trying to recruit Daněk’s help finding Sasha Vesna, Nagel is detained by Marines at the Embassy who also search her office. Her security officer, Kerble, privately smuggles the copy of the video Nagel had given him to Daněk before publicly insisting she leaves. In the silo, the Golem begins the process of detonating the liquid hydrogen, giving him 20 minutes to escape before the explosion.

Langdon and Solomon are pursued by an unknown man down a dark tunnel extending beneath the facility. Langdon attempts to trick the pursuer by triggering the automatic lights in one hallway but hiding in a doorway, but the man is not fooled.

As Finch approaches Langdon and Solomon’s hiding spot, they are able to push through the door into a long hallway. Langdon realizes the door was held open by a small wad of fabric, and Solomon warns that they are now trapped inside with whoever was hoping to exit via the door.

Langdon and Solomon follow a long tunnel to another secured room, which Langdon recognizes as an underground bomb shelter. Inside, they find advanced suspended animation machines like the ones in Gessner’s lab. Solomon tells Langdon that Threshold is a death lab.