The doc shows the beginnings of Eilish's infatuation with Bieber -- in one scene, she shares a clip of her 12-year-old self worrying that her future loves will have to compete with her affection for Bieber. "I literally remember sobbing into a pillow, because I thought, 'I'm never gonna feel this way about anyone,'" she recalls.
The singer's mom, Maggie Baird, even admits to considering therapy for her daughter, because of how "lovesick" she was over Bieber. However, once Eilish dropped her hit single, "Bad Guy," and began to climb the charts in a major way, it was Bieber who became a fan, dropping into her DMs to share his praise and desire to collaborate with the young singer.
It's the second weekend of Coachella 2019 when it all comes together. The doc shows the family together in Eilish's hotel room, listening to Bieber's verse for the "Bad Guy" remix, which makes Baird tear up. "She's cried over his songs so many times, and now he's singing [her] song!" she marvels.
Eilish finally gets to meet Bieber in person during Ariana Grande's set at the music festival, where Bieber made a surprise guest appearance -- his first performance in over two years. At first, Eilish runs away from him in the VIP section in front of the stage, but then she gets past her starstruck shock and embraces her idol-turned-peer.
"I literally cried in his arms for, like, five minutes," she says after the show, later sharing a heartfelt message that Bieber sent her.
"It's moments like tonight when I'm reminded what I mean to people," she reads to her family, in between speechless moments. "Your love for me touched my heart. You are so special, not for what you can do, but for who you are. Remember that."
"I am so impressed by your aura at present. You carry a heavy calling. You are an idol to so many. I'm excited to watch you flourish. You are beyond special. Thank you for tonight. It meant just as much to me as it meant to you. I also want to let you know, it feels like yesterday I was 15, singing 'One Time,' and now I'm 25 and that was 10 years ago. It flew by in a flash. Enjoy every minute of what you are experiencing. Embrace it all. Believe you are great, but not greater than anyone."
Bieber reached out again after Eilish's historic night at the 2020 GRAMMYs -- where she and brother Finneas swept the major awards: Album of the Year, for her debut, When We All Fall Asleep, Where Do We Go?, Record and Song of the Year for "Bad Guy," Best New Artist and Producer of the Year for Finneas. One of the final scenes of the film shows Eilish unwinding backstage after the non-stop awards show, when she receives a FaceTime call from Bieber. The "Sorry" singer sends a special shout-out to Finneas before sharing how proud he is of Eilish.
"How does it feel? Everything you've ever imagined?" he asks. "That's awesome. I'm proud of you. You've been working for this."
The documentary's director, R.J. Cutler, spoke with ET's Katie Krause about filming with Eilish and her family for nearly 140 days over the course of about a year, charting the young performer's success from viral sensation to global superstar, and watching her receive support from not only Bieber, but Orlando Bloom and Katy Perry, whom she also meets at Coachella. Knowing the world of teenage pop stardom can be a "crazy road," Perry tells Eilish to call her if she ever wants to talk.
"[Katy says] welcome to this world, and know if you need a friend, if you need someone to talk to, know that I'm here," Cutler said of the meaningful moment. "Not many people experience the things that these guys do."
Coming from Bieber, Cutler said, the message was even more meaningful, not just because Eilish was such a big fan, but because the singer has been incredibly candid in recent years about his own mental health struggles after finding fame at a young age. "He says to her to at a certain point in the film, 'You remind me of what I mean to people.' That's pretty special."
"The thing I think about Justin is that this is a real person... a real kid who took on the burdens of being his generation's kind of shaman, you know, and speaking so much to kids of his generation, and meaning so much to them," the director noted. "It impacts you. Of course, it gives you great wealth and many things, but again, it's complicated."
"The same is true of Katy," he added, "and that they both make it their business to say to Billie as she walks into that room, that very rarified territory, 'Know that I'm here for you,' I find that awesome."