Nate, Forsyth, and a technical officer monitor the Kämp Hotel meeting from an adjacent room using hidden cameras. Gable waits outside in a van with four FBI agents.

Volontov, Dominika, and their US contact, John Paul Bullard, enter the room. Dominika perceives danger through her synesthetic ability. Bullard identifies himself as a National Communications Service analyst and presents the manual. Volontov directs Dominika to secure it in the bathroom, where she successfully swaps the real manual for the substitute. Back in the room, she translates as Volontov offers Bullard only $5,000 until the manual is authenticated, then instructs him to wait five minutes before leaving.

After Volontov and Dominika depart, Bullard doesn’t wait; he immediately exits. Despite Forsyth’s hold order and Gable’s warnings, the FBI team rushes into the lobby and arrests Bullard. Volontov’s counterintelligence officer, watching from the crowd, witnesses the arrest and slips away unnoticed. Forsyth condemns the FBI’s premature action, hoping that the Russians didn’t see it.

Forsyth orders Nate to have no contact with Dominika and let the situation develop. The next day, Gable reports that an asset saw Dominika and two men leave the embassy with a diplomatic bag, heading to the airport. Nate insists on observing her there, and at the airport, they spot Dominika between a security man and an administrative officer. Nate and Dominika make eye contact, and she gives an almost imperceptible shake of her head. He nods in understanding.

In Helsinki, Dominika senses danger from Volontov’s demeanor before her departure. When they arrive in Moscow, two men escort her to an SVR building on Ryazanskiy Prospect. Colonel Digtyar of Directorate K interrogates her about the Helsinki operation. She maintains her innocence, and they release her after taking her passport.

At home, her mother Nina immediately understands the danger. Dominika’s interrogations resume the next day, with multiple officers searching for inconsistencies. That night, Nina plays violin and whispers that Dominika’s late father despised the system, urging her to resist and survive. Dominika realizes that her mother knows what is happening.

The next day, Dominika is taken to Lefortovo Prison, stripped, and issued a prison smock. Over a period of weeks, she endures isolation, sleep deprivation, beatings, stress positions, and electrocution. A female guard sexually assaults her during questioning; Dominika confronts her verbally. A planted cellmate attempts to befriend her, but Dominika sees through the informant. A colonel’s psychological manipulation nearly breaks her—forcing her to read dissident trial transcripts and blaming her for Marta Yelenova’s death—but she resists by focusing on her identity, her mother’s words, and memories of Nate.

In Washington, Benford’s disinformation campaign convinces the SVR that the acquired manual is authentic, which he hopes will also protect Dominika. The Kremlin celebrates the operation as a major success, and President Putin promotes Vanya Egorov to lieutenant general. Vanya subsequently orders Dominika’s release, and Colonel Digtyar escorts her out of Lefortovo.

Dominika recovers at home, using ballet exercises to heal physically and psychologically. In Vanya’s office, she calmly references the torture and requests assignment to General Korchnoi’s Americas Department. She persuades Vanya to let her resume the operation against Nate Nash, claiming that they became intimate, and she can identify the mole. She flatters Vanya, telling him he created her. He agrees. General Korchnoi welcomes her to his department, privately commending her survival, and he and Vanya agree to restart the operation, with Korchnoi supervising.

A month after Dominika’s recall, Nate is at CIA Headquarters, distraught over her unknown fate. A flashback reveals that he had requested leave to travel to Moscow to find her. Forsyth furiously denied the request as dangerously unprofessional, and Gable told him to stop grieving.

Nate has been reassigned to the Central Eurasia/Russian Ops Desk in Langley, Virginia, where the chief manages Russian cases worldwide, reading daily reports from stations about recruitment prospects and handling existing agents like MARBLE. The Chief summons Nate and informs him that MARBLE has signaled from New York, where he is attending the UN General Assembly. He assigns Nate to handle the meetings and instructs him to first meet with Simon Benford in the Counterintelligence Division, warning him to impress Benford with his operational management.

Nate meets MARBLE in a Midtown hotel suite. MARBLE reports that SVR is likely running an illegal agent in New England, targeting the US ballistic submarine program. Regarding the Director’s Case, he mentioned in Helsinki, MARBLE reports hearing Vanya Egorov mention a cryptonym LEBED—meaning SWAN—and he suspects it refers to a high-level source inside the US government. He suggests investigating Washington Rezident Golov and requests to speak directly with Benford.

Two days later, Benford meets MARBLE in a different hotel. MARBLE confirms his intelligence and announces his intention to provide a successor: Dominika Egorova. Benford is shocked to learn that she is alive and that the two agents know each other. MARBLE explains his plan: Having brought Dominika into his department, he will use Vanya’s renewed operation against Nate to establish her as his protégé. Dominika will “discover” that MARBLE is the CIA mole and turn him in—making her a hero within the SVR and guaranteeing her long-term access as his successor, the next major penetration agent.

That evening, Benford and MARBLE debate the plan over dinner. Benford argues it is reckless and monstrous, questioning the necessity of such a sacrifice. MARBLE insists that it is essential to ensure intelligence continuity. Benford reluctantly agrees to proceed incrementally on two conditions: Neither Nate nor Dominika will be told.

When he returns to Langley, Benford summons Nate to his chaotic office in the Counterintelligence Division. Benford questions Nate’s trust in MARBLE and the intelligence’s authenticity. He then officially assigns Nate to work directly for him on the MARBLE leads, demanding absolute secrecy from all agencies, including the FBI.

Nate is given a sparse office and meets his colleague Alice, a division veteran who begins mentoring him. They are joined by Sophie, a submarine analyst, who identifies the Electric Boat Shipyard in Groton, Connecticut, as the most likely workplace for an illegal targeting the submarine program. After three days searching personnel databases, Nate and Alice present a short list to Benford, who immediately identifies Jennifer Santini, an employee in supply and procurement, as the prime suspect. He announces they are traveling to New London, Connecticut, to investigate.

Nate and Benford travel to New London, and for four days, they conduct surveillance on Jennifer Santini’s house and neighborhood. They find no evidence of clandestine activity. Benford insists on avoiding FBI involvement, believing that Santini would detect a law-enforcement approach and escape.

On the fourth night, Benford announces that they will perform an unauthorized covert entry the next morning. Nate enters, finds the house empty, and lets Benford in. The house appears impersonal and ready for quick abandonment. Nate discovers a rolled submarine blueprint hidden in a desk drawer; upstairs, Benford finds a handwritten transmission schedule in a bedside table.

Before they can confer, Santini unexpectedly returns home. A heavily muscled bodybuilder, she attacks Nate with extraordinary speed and strength, pinning him against a wall, then hurls a coffee table at Benford, who retreats upstairs. Nate grabs a fireplace poker and, drawing on his hand-to-hand training, strikes Santini on the neck, killing her instantly. Shaken, they collect their evidence, and Benford decides to call in the FBI to handle the crime scene.

Dominika begins work under General Korchnoi, who informs her that they will take an operational trip and must first meet with Vanya Egorov. She feels guilt about deceiving Korchnoi but considers it necessary to recontact the Americans. She reflects on her ambiguous feelings for Nate and the power her secret provides.

Vanya enthusiastically approves the operational travel to re-engage Nate. Walking back to their office, Dominika and Korchnoi pass Matorin in the hallway, triggering a strong reaction of fear and rage in Dominika, though he does not appear to recognize her.

That evening, Vanya is summoned to meet President Putin in the Kremlin. He briefs Putin on the success of the communications manual acquisition and ongoing intelligence from the Washington asset, SWAN. Putin stresses protecting SWAN and reveals that he knows the asset is female.

Vanya describes his plan to compromise Nate Nash and identify the mole. Putin, demonstrating detailed knowledge of the operation—including that the officer is Vanya’s niece and was recently investigated—authorizes it but explicitly forbids active measures like abduction. As Vanya’s car leaves the Kremlin, Zyuganov’s car heads, unseen, toward the Senate building.

US Senator Stephanie Boucher, vice chair of the Senate Select Committee on Intelligence (SSCI), arrives for a clandestine meeting in Georgetown. Ambitious and contemptuous of the CIA, her lack of restraint makes her an appealing recruitment target. A flashback details how a talent spotter identified her potential, and SVR Washington Rezident Anatoly Golov cultivated her by providing Russian intelligence analysis that she used to advance her career.

Motivated by power and money, Boucher became an active source codenamed SWAN, providing minutes of closed SSCI sessions and classified testimony. Her most valuable access is to a top-secret Special Access Program for a space-based weapons platform—the Global Orbiting Vehicle (GLOV), capable of launching pinpoint strikes from orbit—managed by Pathfinder Satellite Corporation in her former congressional district.

Golov meets Boucher and reflects on her extraordinary value and volatility. She demands confirmation that the SVR will pay her latest request, threatening to stop providing intelligence otherwise. When Golov urges her to adopt more secure tradecraft and reduce personal contact, Boucher refuses dead drops or covert communications, insisting on meeting only with him personally. They compromise on private hotel suites in Washington. Boucher demands access to her secret SVR bank account in Liechtenstein, which Golov explains violates security protocol. As she leaves, she gives him a disc containing recent SSCI hearing minutes about Pathfinder. Golov remains at the table, composing a cable to Moscow.