The alarm is a civil defense warning that goes off on every phone, followed by hotel-wide alarms and a power outage that plunges the restaurant into chaos. Alice initially fears that Vivien has abandoned her, but her mother grabs her by the arm, and a security guard leads them outside into a city-wide panic of car crashes and shrieking sirens. Alice feels a pang of guilt for not trying to help a father and child trapped in an elevator. The alarms abruptly cease, and a phone alert confirms that the alarm was global, though no one knows what precipitated it. Later, at Vivien’s Georgetown home with her brother, Kevin, and his partner, Paul, news reports detail the worldwide scope of the incident: All electronic alarm systems, from residential burglar alarms to the warning system on the International Space Station, went off at once, and then stopped. Meanwhile, Alice considers her secret, which she plans to reveal to Vivien at the appropriate time—that Kevin is gay and that he and Paul are married. As far as Vivien knows, Paul is only Kevin’s friend. Vivien emerges from her study and, to everyone’s surprise, instructs Alice, and not Kevin or Paul, to accompany her to a waiting government vehicle.

Alice and Vivien are driven to the White House and escorted to a secure meeting with top officials, including Grant McAllister, the Director of National Intelligence, who addresses Alice directly in Mandarin, thanking her for coming. Alice is baffled as to why she has been invited to this meeting and why everyone seems to be looking at her. The meeting turns out to be about Alice’s friend, Liam Palmer. The officials show Alice Liam’s selfie from Hong Kong and question her about their relationship and his work as a food company account manager, though all the information they ask about is already public record. McAllister then reveals that Liam was found dead in Hong Kong harbor. He tells a stunned Alice they believe he was murdered and that his death is connected to the global alarm event, which they have traced back to China.

President Pardington and his Chief of Staff, Kathleen Wells, join the meeting. The president confirms that malware created in China triggered the alarms simultaneously across the globe. The group’s central problem is understanding the motive behind the attack, as no demands have followed the “warning.” They analyze the message Liam sent Alice, which contains a literary quote, the Chinese characters for “fish balls,” and a misspelling of the island “Cheung Chau,” which Alice notes privately should be spelled “Chueng Chau”—an island off Hong Kong, known for its fish balls. Many of the people at the table are supposedly China experts, and Alice wonders why they don’t know this. Alice dismisses the somewhat cryptic message as playful: Food bloggers like to create puzzles for other food enthusiasts. Unsure what to make of the situation, the president turns to Vivien for her expert analysis.

Vivien identifies two men in Liam’s photo as agents from the MSS, China’s secret police, implying that Liam was involved with them. She theorizes that Chinese President Chen’s power is weakening and that other senior officials exert greater influence from backstage. She also suggests that the alarm—which puzzlingly was not followed by any demand or warning—was a form of psychological warfare, designed to create terror through uncertainty. Vivien then stuns the room by revealing that she has a photograph of the unidentified woman poised to replace the current MSS head, a sign of major instability. She concludes with a cryptic warning: The only thing worse than the Chinese government being behind the attack is if a rogue faction they cannot control was responsible.

In the car home, Vivien silently signals to Alice that they are being monitored. She covertly instructs Alice to go to Columbia University in person to get Liam’s family’s address. Back at the house, Alice breaks down while telling Kevin and Paul that Liam is dead. Later, she recalls the famous photograph of an unidentified man standing in front of advancing tanks in China’s Tiananmen Square in 1989. Rumors have long circulated that the man, colloquially referred to as “Tank Man,” was Vivien’s boyfriend at the time—rumors that Vivien has neither confirmed nor denied. Alice recalls that as a teen, she used to fantasize that this man was secretly her father and would one day arrive to rescue her from Vivien’s tyranny. She remembers her real father, whom she loved and who died in a car accident when she was 12. She resolves to confront her mother.

Meanwhile, at CIA headquarters, analyst Alan Zhou accesses a secret file as a colleague teases him for having been undermined by Vivien in front of the president. Vivien’s claim that the MSS head is about to be replaced made Zhou look foolish, as he had no such information. He suspects Vivien is making it up, but the president clearly believed her. Zhou discovers a photo from the Tiananmen Square protests that appears to show a younger Vivien in uniform, aiming a rifle at Tank Man, though he suspects it may be a forgery.

In her study, Vivien reveals that she is a spy working for the US government and that Liam was an intelligence asset working under her, using his food blogger persona as a cover. She admits that Alice’s friendship with him was a convenient explanation for their connection, making Alice a “useful idiot.” Stung, Alice presses Vivien about her past. Vivien confesses that “Tank Man” was her brother, Kai-wen, who was later arrested and died in a prison camp, fueling her lifelong crusade. She also confirms that neither she nor US intelligence knew about Liam’s final trip to Hong Kong, suggesting that he was on a secret mission. Vivien believes a powerful rogue element within China, not the government itself, orchestrated the attack and that another is imminent.

Alice travels to Columbia University, where she meets an old classmate, Jen. They organize an impromptu wake for Liam at a bar with friends, including his former roommate, Jack. As they reminisce, Jack recalls a time Liam went into anaphylactic shock at a Thai restaurant after eating what they assumed was a prawn curry, revealing a severe shellfish allergy. This story strikes Alice as a major contradiction, as Liam’s recent food blog posts often featured shellfish. On the train back to DC, Alice realizes the Thai curry and the coconut bun in Liam’s final photo are connected. She googles the curry’s ingredients and has a sudden, shocking realization about the true nature of his allergy.