Will Ferrell began crying Sunday night as director Josh Greenbaum hailed the love he and former Saturday Night Live writer Harper Steele bring to the screen in their new Netflix film Will & Harper.

In the film, Ferrell reconnects with his long-time friend, who for the first 61 years of her life lived as a man. Moving forward with a determination to be her most authentic self, Steele is invited by Ferrell to road trip across the U.S. With cameos from Tina Fey, Seth Meyers and Kristen Wiig, Greenbaum’s film is equal parts joyful and poignant. The tenderness of the pair’s relationship is moving and palpable as the pair navigate their friendship — and Harper, her newfound womanhood — through the various stops along the way.

“I don’t wanna make a mistake, I don’t want to ask in the wrong way,” Ferrell confessed during a Q&A at a London preview of the film held at BFI Southbank. “We just wanted to capture a conversation between two friends, and just bring it down to that level that hopefully the audience can listen to me stumble my way through asking my dear friend these questions… She allows me to make those mistakes and encourages me to ask away.”

There were some not-so-dry eyes in the room when Greenbaum paid tribute to Ferrell and Steele for their participation. “I have such a love for him, for both of these people, it was a gift that I got to express it in a film.

“But I just hope [Ferrell] continues to get all the love that he deserves,” Greenbaum continued. “Because he’s put so much good out in the world. And we often sometimes take for granted comedians who give us joy and love throughout our whole lives and make our day-to-day a lot easier, so I hope he feels that.” As Ferrell wiped away tears, Steele lightened the heartfelt moment and joked: “What is this bullshit?”

Will Ferrell starts crying at a preview of WILL & HARPER when director Josh Greenbaum talks about how he hopes Will and Harper can feel the same love they’ve brought to the screen in this lovely film 🥹 @THR pic.twitter.com/AlyIpVs1tX

— Lily Ford (@lilyfordtweets) September 15, 2024

Steele spoke about being emotional herself while in London after Ferrell said the trio have stopped at Sundance, Toronto and Telluride Film Festivals. “I was in London shooting a film with Will right before the pandemic, about the Eurovision Song Contest,” she said. “And I was right on the cusp of this experience, but this was a difficult period for me in London. And walking around London, going to get my [U.K. bakery chain] Greggs sausage as myself, finally, it was just so much joy. Thank you.”

Ferrell was asked about his highlights from the 16-day trip with Steele. “Every day there was a highlight,” he said. “We try to make each other laugh all the time. And the highlights ranged from Harper showing us photos of herself on a unicycle, the way she used to get around Iowa City, only to be in front of her childhood house and this young person to come up on a unicycle… Insane.”

“And even though they didn’t recognize me,” he continued, prompting laughter from the BFI Southbank audience, “Then Harper gets on and rides this unicycle in heels. Between that and our chance encounter at the Grand Canyon with a retired therapist who is trying to make amends for a situation she didn’t feel like she knew how to handle and Harper giving her comfort. Me getting to surprise Harper at a pool with my speedo… So many highlights.”

Will & Harper, which premiered at Sundance in January, will be available to stream on Netflix Sept. 27. It will also be released in select theaters on Sept. 13.

Will Ferrell was filming the Christmas musical comedy “Spirited” in Boston in 2021 when he received an email from an old friend — a writer who had championed Ferrell in his early days at “Saturday Night Live,” and had collaborated with him on a number of outside-the-box projects, including the Spanish-language “Casa de mi Padre” (2012), the Lifetime movie “A Deadly Adoption” (2015) and “Eurovision Song Contest” (2020).

The email read in part: “I’m old now, and as ridiculous and unnecessary as it may seem to report, I’ll be transitioning to live as a woman.”

That old friend’s name is Harper Steele, and she had made the decision to come out in her 50s. While Ferrell was instantly supportive, he had questions for Harper — and she had questions for him — and at Ferrell’s suggestion, they set out for a 16-day road trip across the country, with Harper at the wheel of her rickety but classic wood-paneled Jeep Grand Wagoneer.

Director Josh Greenbaum (“Barb and Star Go to Vista Del Mar”) and a camera crew were also along for the ride, filming Ferrell and Steele as they made their way from snow-covered Staatsburg, New York, to the beach at Santa Monica, California, with stops along the way including Washington, D.C.; Iowa City, Iowa; Oklahoma; Texas; Las Vegas, and New Mexico. The result is the warm and funny and touching Netflix documentary “Will & Harper.”

Although this is the antithesis of a fly-on-the-wall chronicle, what with Will Ferrell being WILL FERRELL, it’s still an emotionally honest and deeply moving look at two friends bonding after one of them has found the courage to be her true self. (As Kristen Wiig sings in a little ditty she and Sean Douglas wrote for Harper and Will, “A friend is a friend is a friend, till the end.”)

Harper has long enjoyed taking road trips, hitting honkytonks and greasy diners, and drinking what Will describes as “s- - -ty beer,” but she wonders if she’ll be accepted now. “I love [this country] so much,” she says. “I just don’t know if it loves me back right now.”

The journey includes a stop at 30 Rock, where Harper and Will share hugs and laughs with Lorne Michaels, Tracy Morgan, Tina Fey, Tim Meadows, Seth Meyers and Colin Jost, and there’s an interlude in Albuquerque where they take a hot-air balloon ride with Will Forte.

Mostly, though, “Will & Harper” is about the conversations between Ferrell and Steele when they take out lawn chairs and watch the sun set and sip from cans of beer, and their journey across Middle America and the Southwest, with stops at a biker bar and diners and gas stations, an Indiana Pacers game, a dirt race track and the Grand Canyon.

As Harper readily points out, she has the benefit of being with the beloved Will Ferrell (not to mention a camera crew), which surely affected some interactions. Folks are often friendly and supportive, clinking beers with Harper and posing for selfies with her and Ferrell.

Occasionally someone mistakenly calls Harper “sir” or “bro” and is gently corrected. And Ferrell’s penchant for wacky antics sometimes backfires, particularly when he inexplicably dons a Sherlock Holmes costume for a foray into a jam-packed Texas restaurant and attempts to polish off a 72-ounce steak, with Harper sitting across from him. A sea of smartphones emerges, dozens of videos pop on social media — and the bigoted trolls come out in all their ugliness, posting cruel and hateful messages.

There’s also no shortage of laughs. After all, both Harper Steele and Will Ferrell have been professionally hilarious for 30 years. Their banter is fast and funny, with Ferrell sometimes diving into shtick, as when he says if they don’t stop at a Dunkin’ Donuts, the whole trip will be ruined.

Most memorable, though, are the quieter sequences, e.g., when Harper and Will relax in an otherwise unoccupied hotel pool at night and talk about their respective body image concerns. “I think you look great,” says Will, and Harper replies, “Thank you. ... I do believe that you really mean that.” These are two old friends, trusting each other, being honest with one another, sharing with one another. It’s just lovely.