At midnight on Friday, Ariana Grande released the much-awaited follow-up to “Thank U, Next,” a dreamy, waltzing ballad called “Imagine.” In the song, Grande—you guessed it—imagines an alternate universe in which some unspecified relationship worked out and has reached “eating takeout and taking bubble baths together” levels of idyllic. Immediately upon the track’s release, fans took to Twitter to marvel at the four impossibly high whistle tones Grande hits toward the end of the song, and to theorize about the subject of the song, a task made significantly more difficult this time around, since Grande neglected to name names in “Imagine” as blatantly as she did in “Thank U, Next.”

Despite a lack of concrete evidence, however, the prevailing fan theory is that the song is about Grande’s late ex-boyfriend, Mac Miller. For one thing, Miller, who died of a combined fentanyl, cocaine, and alcohol overdose in September, had a large tattoo of the word “Imagine” on his inner bicep. For another, a line about Grande’s love of stir-fried dishes in her new song mirrors one in Miller’s “Cinderella,” which Grande previously confirmed is about her: In “Imagine,” Grande sings, “Staying up all night, order me pad thai,” while in “Cinderella,” Miller raps, “And when you hungry I can chef you up a stir-fry.” Elsewhere in “Cinderella,” Miller raps, “You used to tell me all the time I ain’t your type,” which, again, seemingly parallels a moment in “Imagine,” where Grande sings, “Feels like forever, baby, I never thought that it would be you.”

Furthermore, several fans pointed out that the last time Grande even attempted those whistle tones in a track was in 2013’s “The Way,” her first collaboration with Miller. Incidentally, in her recent Billboard Woman of the Year interview, Grande shared that recording that song represented a major turning point in her career. “When we made ‘The Way,’ I was like, ‘Oh, wow, I’m onto something here,’” she said, adding, “It felt like, ‘I should do this forever,’” a sentiment that, in itself, mirrors the aforementioned “feels like forever” line in “Imagine.”

For her part, although Grande hasn’t explicitly stated whom the song is about, she has elaborated on its general subject matter. In November, when fans spotted the titles of some of her upcoming songs, including “Imagine,” hidden in her “Breathin’” music video, Grande explained that the song concerns “a simple, beautiful love that is now (and forever) unattainable,” which is, perhaps, another hint that it’s about Miller.

“I would say if 'thank u, next' = acceptance... 'imagine' = denial. hope that makes sense,” she further explained on Instagram earlier this week. She clarified in a follow-up tweet, “kind of like... pretending [a breakup] never ended. denial. but i look forward to you hearing it and having your own experience with it. you may take away something totally different and specific to your life! love u.” And when another fan asked if “Imagine” is her favorite song off her upcoming album, Grande replied, “it’s very very special to me.”

Related: Ariana Grande Is Not Apologizing for Openly Mourning Mac Miller