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

The email read, in part: “I am old now, and as ridiculous and unnecessary as it may seem to report this, I am going to undergo sex reassignment surgery to live as a woman.”

This old friend’s name is Harper Steele, and she had decided to come out in her 50s. While Ferrell was immediately supportive, he had questions for Harper – and she had questions for him – and at Ferrell’s suggestion, they set off on a 16-day cross-country road trip, with Harper behind the wheel of their beat-up but classic wood-paneled Jeep Grand Wagoneer.

Director Josh Greenbaum (“Barb and Star Go to Vista Del Mar”) and a camera crew were also on hand to film Ferrell and Steele on their way from snow-covered Staatsburg, New York, to the beach in Santa Monica, California, with stops in Washington, DC; Iowa City, Iowa; Oklahoma; Texas; Las Vegas and New Mexico. The result is the warm, funny and touching Netflix documentary “Will & Harper.”

While this is the opposite of a gaudy chronicle, since Will Ferrell is WILL FERRELL, it is still an emotionally honest and deeply moving look at the friendship between two friends after one of them finds the courage to be herself. (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, to the end.”)

Harper has long enjoyed road trips, going to honky-tonks and seedy diners and drinking what Will describes as “shitty beer,” but she wonders if she’s accepted now. “I love (this country) so much,” she says. “I just don’t know if it loves me back right now.”

The trip includes a stop at 30 Rock, where Harper and Will hug and laugh with Lorne Michaels, Tracy Morgan, Tina Fey, Tim Meadows, Seth Meyers and Colin Jost, and an interlude in Albuquerque, where they take a hot air balloon ride with Will Forte.

But most of all, “Will & Harper” is about the conversations between Ferrell and Steele as they sit on lawn chairs watching the sunset and sipping canned beer, and their journey through the central United States and the southwest, with stops at a biker bar, diners and gas stations, an Indiana Pacers game, a dirt track and the Grand Canyon.

As Harper readily points out, she has the advantage of being around the popular Will Ferrell (not to mention a camera crew), which has certainly influenced some interactions. People are often friendly and helpful, toasting Harper with beers and posing for selfies with her and Ferrell.

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

There’s no shortage of laughs either. After all, both Harper Steele and Will Ferrell have been professional comedians for 30 years. Their lines are quick and witty, with Ferrell sometimes getting ridiculous, like when he says if they don’t stop at Dunkin’ Donuts, the whole trip is ruined.

But the most memorable scenes are the quieter ones, like when Harper and Will relax at night in an otherwise unoccupied hotel pool and talk about their respective body image concerns. “I think you look great,” Will says, and Harper responds, “Thank you. … I really think you mean that.” These are two old friends trusting each other, being honest with each other, and sharing with each other. It’s just wonderful.