Park was sitting nearby, in a shaded corner that served, for the day, as video village, the spot on a film set where the production team gathers around monitors to review each take. At sixty, Park, who is Korean, has a mop of silver hair and an obscurely regal demeanor. He wore woven leather sandals and vented performance gear, as if he were about to go fishing. Nearly everyone referred to him as Director Park, following a Korean practice of using the title as an honorific. On set, at any given moment, you could hear Thai, Vietnamese, Korean, and English being spoken, but the action was mainly directed in English. Park understands and reads the language well, but he’s not the type to risk miscommunication. His instructions were relayed to the cast and crew by Jaehuen Chung, a filmmaker who served as Park’s interpreter.

The shot they were trying to get was relatively straightforward. A Citroën driven by the show’s protagonist—a Communist double agent simply called the Captain—would push its way through the distress of the crowd. Working alongside Park was a co-producer named Jahye Lee, who had served as the script supervisor on his most recent film, the slow-burning noir romance “Decision to Leave.” She and Park were sharing a bag of salty tempeh snacks. Each time a new take began, they sat up straight in their director’s chairs in perfect tandem.

Park has a gift for sumptuous spectacle underpinned by meticulous preparation. He storyboards his movies from start to finish before shooting begins, and presides over the details of his filmic universe like a clockmaker god. He has an unapologetically showy style that draws on a promiscuous cinematic education—Akira Kurosawa and Kim Ki-young, Alfred Hitchcock and Robert Aldrich, forgotten B movies and contemporary genre films—and a conviction that everything is permissible and nearly anything is possible. His camera skitters, glides, flummoxes. How, you might find yourself wondering, while watching “Decision to Leave,” did he shoot a mountain from inside the eye of the dead man at its base?

Park called cut and moved one of the soldiers in the frame slightly to the right. Filming resumed, then he called cut again: one background actor, among dozens, needed to look up at the road earlier. There was a pause. “Just waiting for this cloud to move,” a beefy guy said into a walkie-talkie. The sky brightened. The Citroën rolled through the barricades once more—Episode 101, Scene 47, take four.

This was day eighty of production. All in all, the shoot for “The Sympathizer” would take a hundred and twenty days. While Park and his crew tried to get the Citroën scene right, a construction team of nearly two hundred people was building a more or less fully equipped replica of a reëducation camp, close to the Malaysian border. It would provide the setting for the show’s frame story: the Captain, after the war, has been imprisoned, and is narrating his journey between worlds—he ultimately makes it out of Vietnam, and heads to Los Angeles—to an unseen, unamused superior.

“The Sympathizer” is the product of a marriage between two eminent tastemakers, A24 and HBO. It was green-lighted three years ago, late in the era of so-called Peak TV, when cable networks and streaming services chased market dominance by throwing money at big-name talents who wanted to work on ambitious projects. HBO was the reigning power of this period. But, by the time of my visit to set, the network was at the center of new industry contractions. A year after “The Sympathizer” went forward, HBO’s parent company was bought by another network, Discovery, known mostly for its reality shows. Discovery’s C.E.O., David Zaslav, took on more than fifty billion dollars in debt to complete the deal, and soon began shelving movies for tax writeoffs. Across the industry, streamers turned off the development-money tap as executives became risk-averse. Profits weren’t satisfying investors, and the prospect of a writers’ strike loomed.

“The Sympathizer,” which features zero wealthy white people sniping at one another in luxury settings, was always a risky bet. The cast includes a handful of well-known actors—Sandra Oh, John Cho, David Duchovny—mostly in supporting roles. Its biggest star, Robert Downey, Jr., was reportedly paid two million dollars per episode to play four different parts: a C.I.A. agent, a conservative congressman, a professor with a fetish for “the Orient,” and a filmmaker shooting a movie with a passing resemblance to “Apocalypse Now.” But the events in the show are narrated from a distinctly Vietnamese perspective—the series opens by reminding viewers that, in Vietnam, the conflict is called the American War. At one point, an American college student asks the Captain, played by the young Vietnamese Australian actor Hoa Xuande, if he appreciated the efforts of protesters in the U.S. The student proclaims that they were on “the side of the Vietnamese people.” The Captain says, “Which people? The people in the North or the people in the South?” The student, stymied, answers, “All of them, I guess.”

Park put on a big khaki hiking hat. Chung relayed another instruction: the Citroën should drive faster onto the bridge. Park told the show’s visual-effects supervisor that there should be stars on the car’s license plate, and that he wanted to digitally remove one of the buildings in the background. The sequence would culminate in the Captain desperately running to board a moving plane, surrounded by people carrying the wounded and the dead. By then, the sky, in Nguyen’s description, is a “meteorite shower of rockets and artillery shells . . . an apocalyptic light show that revealed the evacuees dashing for the concrete divider, stumbling and tripping along the way, suitcases forgotten, the thundering prop wash from the two remaining engines blowing little children off their feet.” To film the scene, the crew would affix the back half of an airplane to a truck, rig cranes with lighting to simulate phosphorus explosions, put up enormous fans to create whipping propeller winds.

“The craft is at as high a level as the art,” Alec Hammond, the production designer for the Thailand shoots, told me. “Take the evacuation—how do you get actors carrying people or dummies into a plane to carry all that real emotion? How do you put that set together in a way that it’ll move at fifteen miles per hour, that it’s safe, that you can reset between takes?” Park’s sets are notoriously calm; he wraps early more often than he asks people to stay late. Hammond told me that there is a surety to Park’s filmmaking that allows it to be efficient: “When he gets it, he knows it, he knows how he’s going to use it, and he can stop.”

There was a break. Video village was next to a bridge, which arched over a murky river. Next to the river was a tree, and someone had noticed a mottled python curled around one of its branches. Burly guys from the crew gathered to look at the snake. Park ambled over, hands behind his back in an avuncular pose. His manner can resemble his movies—patient, intense, with no wasted motion. He craned his head in curiosity, trying to see the python, but couldn’t find it. Jahye Lee took a photo of the tree on her phone and zoomed in to show him. He saw the snake then, framed properly on the screen, and smiled.

“Oldboy” provides the brutal tick-tock pleasures of a revenge movie only to deconstruct, sickeningly and expertly, the very notion of revenge. In the end, Oh finds his captor, a former classmate named Lee Woo-jin. Lee, on account of a grudge held since high school, not only imprisoned Oh but also manipulated him, after his release, into unwittingly having sex with his own daughter. In an abject effort to persuade Lee not to reveal this to her, Oh barks like a dog, licks Lee’s shoes, and cuts off his own tongue with scissors. (“If you want a peaceful rest, have a bath,” Park told an interviewer, shortly after the movie was released.) Like most people who watch “Oldboy,” Nguyen found this finale disturbing. But upon rewatching the movie he realized that his ambitions, too, required unsettling people, both stylistically and politically. With “The Sympathizer,” Nguyen similarly tries to upend the reader’s expectations—of a spy novel, an immigrant novel, a political novel. The Captain, disillusioned, ends up captured, back in Vietnam, believing in nothing. The book also shares with Park’s films a pitch-dark, absurdist humor. Its epigraph is a quote from Nietzsche that begins, “Let us not become gloomy as soon as we hear the word ‘torture.’ ” The Captain’s first sexual experience involves masturbating into a raw squid meant for a family dinner.

“The Sympathizer” was turned down by thirteen publishers before being bought by the independent press Grove Atlantic. It sold twenty-two thousand copies in hardcover; then it won the Pulitzer and sold nearly half a million copies in paperback, at which point Hollywood got interested. But it’s a tricky novel, as slippery as its protagonist, and getting an adaptation off the ground was a long process. Early on, a producer told Nguyen that the project was being pitched at a budget comparable to that of “Narcos,” the Netflix series about Pablo Escobar, which reportedly cost around twenty-five million for its first season. The producer said, “We’re hearing that, for that kind of money, we’d need someone on the scale of Keanu Reeves” as the star. “In retrospect,” Nguyen told me, “that’s really racist—not the producer, but what they were hearing. Pedro Pascal is a huge star now, but when ‘Narcos’ first started filming they didn’t have any A-list actors.”

Another producer, Niv Fichman, who was born in Tel Aviv and lives in Toronto, connected Nguyen with the Canadian actor and writer Don McKellar, who’d adapted José Saramago’s “Blindness” as a feature film starring Julianne Moore. Working with non-Americans made adapting the book easier, Nguyen said, because they weren’t “so hung up on their version of the Vietnam War.” McKellar had once written a script with Park—an adaptation of “The Ax,” a Donald Westlake novel about an unemployed man who begins murdering his competitors for prospective jobs—and he persuaded Park to come on board as the showrunner. But Park insisted that McKellar share the task: Park had done television once before, adapting the John le Carré novel “The Little Drummer Girl” for the BBC, and the shoot had been difficult, keeping him away from Korea for long enough that he grew homesick. Making television is a more bureaucratic process than filmmaking, involving more input from more people on more footage. For “The Sympathizer,” Park would direct the first three of the show’s seven episodes and turn the rest over to other directors. He knew “the enormous amount of work and negotiation and diplomacy involved,” McKellar told me.