Writer Viet Thanh Nguyen spent five years bringing “The Sympathizer” to the screen, but it wasn’t until a recent cruise down the Hollywood Freeway that he realized what a big deal the HBO adaptation of his Pulitzer Prize-winning novel truly is.

“Yesterday, I was driving on the Hollywood Freeway with my family, and my son said, ‘Look, there’s a billboard with “The Sympathizer” on it!’” Nguyen said a little more than a week before the limited series premiered on HBO on April 14.

“We immediately pulled over, thankfully, to a safe place, and everybody spilled out of the car to take pictures with a billboard. And you don’t do that with a book. Books don’t get billboards, usually.

“That’s just an example of how vast the scale is, that you can drive on a freeway through LA now and literally see gigantic billboards with the whole cast’s faces. And that’s amazing. Absolutely amazing.”

“The Sympathizer” is the story of the Captain, a South Vietnamese spy for the North Vietnamese during the Vietnam War, a man of two minds, as he says of himself in the novel, whose communist leanings push against his fondness for the United States where he’d studied before the war. The seven-episode limited series follows the Captain from the fall of Saigon to his journey to the United States and eventual return to Vietnam.

Its cast consists almost entirely of actors of Vietnamese origins. Most, such as Australian actor Hoa Xuande, who plays the Captain, are unfamiliar to American audiences, though some will be familiar such as the acclaimed actress Kieu Chinh, who plays the Major’s Mother, and “Paris By Night” emcee Ky Duyen, who plays the General’s Wife.

“The story is about refugees, a traitor, heroes, a spy and love and relationships,” says Chinh, 86, on a call from her Huntington Beach, Calif., home. “This is the first time a Vietnamese novel is brought to the screen, and most of the characters are played by Vietnamese for the first time.

“So, you know, we are all very excited about that.”

Sandra Oh and Robert Downey Jr. also star in the series, with Oh playing university secretary Ms. Mori, and Downey playing four different characters — a CIA agent, a professor, a filmmaker and a congressman — who are antagonists of the Captain in the series.

Part black comedy, part spy thriller, “The Sympathizer” was co-created by Canadian writer-producer Don McKellar and South Korean writer-director Park Chan-wook.

Page to screen

Viet Thanh Nguyen’s debut novel was a literary sensation on publication, earning acclaim for its subversion of genre tropes such as spy novels and war stories while telling a serious, entertaining and often funny story from the point of view of the Vietnamese side of the war.

After it won the 2016 Pulitzer Prize for fiction, Nguyen, the Aerol Arnold Chair of English and a professor of English and American studies and ethnicity at the University of Southern California, set about seeking a home for the story in Hollywood. In 2021, A24 optioned it as a series for HBO, with other producers, including Team Downey, Robert and Susan Downey’s production company, also coming on board.

Nguyen served as an executive producer on the project. McKellar joined as showrunner after Nguyen mentioned he thought Chan-wook would be a dream director, and a fellow producer who knew McKellar had written a script with the South Korean filmmaker, reached out to McKellar.

He also mentioned Sandra Oh as a possible choice for Ms. Mori, and McKellar, a close friend of Oh’s, reached out and got her on board.

Spending time with producers, cast and crew on set and location left Nguyen in awe of the work that went into making his book into a thrilling spectacle of a series.

“I mean, it literally involves hundreds of people working well over a year at a huge cost to make this, whereas I wrote the whole thing sitting in a little room by myself,” Nguyen says.

“Reading and watching are very different experiences and very hard to compare,” he says. “But they’re both immersive in their own ways. The process of interacting with someone’s words, but then conjuring, in my own mind, whatever’s happening is quite different than sitting more passively in front of a screen.

“But when the screen experience works, it can be really incredible, and I think it does work in this series.”

And the literary world seems awed by the adaptation, too, Nguyen says.

“The degree of excitement that this TV series has generated amongst book people is interesting,” he says. “It’s a little bit humbling, like, ‘OK, well, I did publish a book, and people were excited about that.’ But not at this level.”

Casting in Southern California

While much of the cast was found through a global search of the Vietnamese diaspora, the two primary actresses in this story were found much closer to Hollywood, both residents of Huntington Beach.

Chinh laughs when she’s asked how she came to be cast in the series. Shortly after “The Sympathizer” was published, she went to Irvine to a book event for Nguyen and the author recognized her in the audience.

“At that time, he doesn’t know that the book will turn to on-screen,” Chinh says. “So he just says, ‘Oh my God, we have the legendary actress Kieu Chinh in the audience.’ And he said, ‘Hopefully one day if the book turns into a series, you must be one of the characters.’”

Flash-forward five or six years, Chinh and Nguyen are friends, and one day her manager calls her to a meeting with McKellar and Chan-wook.

“We just talked a little bit and they gave me the part,” she says.

Duyen, after 30 years as host of the musical variety show “Paris By Night,” wanted to try something new. Through her friendship with Chinh, she was referred to an agent.

A week or so later, the agent asked her to do a self-recorded audition for “The Sympathizer.” A Zoom audition with Chan-wook soon followed.

“I thought, ‘OK, it’s probably several months that we hear whether or not (she got the part),” Duyen says. “An hour later, my agent told me you got the role, and I started to realize how big this thing is.”

Both Chinh and Duyen left Vietnam at the fall of Saigon on April 30, 1975, a searing time for the Vietnamese people who fled their homeland, an experience that is re-created in the series.

Duyen was only 9, and her memories of that time are vague. For Chinh, the series’ imagined version of those days hit harder.

The loneliness that the Major’s Mother feels in “The Sympathizer” reminded Chinh of her own feelings as a refugee living alone in a North Hollywood apartment when she arrived in the United States after the fall of Saigon, thanks to actress Tippi Hedren’s sponsorship.

“Some scenes I don’t think that I’m doing the job of an actor, but I just relive my real life,” Chinh says. “The huge scene that director Park created for the last days of Saigon, the evacuation. The mortar attacks, the panic of the people pushing each other to get onto that flight. That is exactly what happened to my own life.

“That night, you can imagine, I was overwhelmed with sadness, scared and tears keep coming out to my eyes. My heart was beating fast and I had a heavy feeling. I just relived my past.”

A different view

As a prestige TV series, “The Sympathizer” is made to entertain, and it does that with the multilayered storylines that stretch from the Captain’s present into his future and his past.

But the series also presents a fresh and unfamiliar perspective on the war, that of the Vietnamese people rather than that of American soldiers, as has been seen in films like “Platoon,” “Apocalypse Now,” “Full Metal Jacket” and others. By showing the perspective of the Vietnamese people, whose lives and land were torn apart by the war, it can’t help but educate viewers, too, those involved in the project say.

“I think that this war was unique,” McKellar says. “The first case, but I think still the only real case, where our conception of the war is through the movies. So this show, the first thing it’s doing is saying, ‘OK, Americans, OK, world, let’s look at this from the other side,’ and remind yourself that it was on Vietnamese soil. That the people who suffered most and the people who suffered longest were the Vietnamese people.

“Which isn’t to say that Americans didn’t suffer. They did. But it’s saying, ‘Sympathize with this other side. Put yourself in the other side.’ And then recognize that side also has divisions and also has complexity, and that is much more complicated than you think.”

Susan Downey said she and Robert Downey Jr. were drawn to the project by that same fresh perspective.

“There are so many moments where you’re wrestling with alliances based on preconceived notions,” she said. “You have the hero, the Captain. But wait, he’s a communist sympathizer, but he’s got this love for America. So it’s just all of these swirling conflicts. I think that if we’ve succeeded at all we make people feel all the emotions — there is humor, there is real drama, maybe some tears. More than anything, it gets people talking.”

And when Chan-wook suggested Robert Downey Jr. play four different characters, the actor was all in, Susan Downey says.

“He really relished the opportunity,” Susan Downey says. “He had just come off of ‘Oppenheimer’ and playing Lewis Strauss, who was a very grounded, very real person. And so the opportunity to play these sort of toxic male symbols of the American patriarchy was a lot of fun for him. He didn’t want to shy away from it.”

Duyen noted that the series mocks the hawkish Americans who pushed for the war, but also satirizes the Vietnamese political and military leadership whose actions led to the downfall of South Vietnam.

“It’s a satirical look at every different side,” she says. “And I think every side will come out feeling a little bit good about themselves, and then a little bit bad about themselves.

“I think also what it does is bring out a better understanding, so that every side can see its effect on the other side. Try to have an open mind. Try to laugh about it. Then I think maybe you can understand each other more.”

Just as American movies such as “Platoon” shaped impressions of the Vietnam War in the ’70s and ’80s, so will “The Sympathizer” shape views of it today, Nguyen says.

“For better and for worse, this TV series will not just be an entertainment, but also function as a history lesson for many, many people,” he says. “This will be their first exposure to the war in general, and for those who know anything about the American perspective, it’ll be their first exposure to any Vietnamese perspective.”

“I think it would obviously be better if people read history books,” Nguyen says, laughing. “Because this TV series cannot offer that same depth as a history book.

“On the other hand, what the TV series can offer, as with literature, is a deep immersive identification through narrative and characters. And that is actually really, really powerful. American Vietnam War movies made an enormous emotional impact on a lot of people. So I think this TV series will have that same kind of impact.”