Following her instant-classic breakup banger “Thank U, Next,” Ariana Grande is back with a sadder, longing track called “Imagine.”

The song, like “Thank U, Next,” reflects on a past relationship. But instead of pushing herself to move on, in this track Grande dwells in what could have be, which immediately led fans to wonder if this track is about her late ex Mac Miller. We've also known a track about Mac was on its way

Miller died of an accidental overdose in September, affecting Ariana in a number of private and public ways. For a number of different reasons, fans believe Grande is using this song to mourn what could have been.

In her own words, “Imagine” is about "pretending it never ended. denial." 

One of the biggest clues this song is an ode to Miller is the large “Imagine” tattoo on his arm.

People also compared lines from “Imagine” to the rapper’s song about Ariana called “Cinderella,” which was released back in May. Like this line about pad Thai: 

There’s also corresponding references to sleeping. In “Imagine,” Grande sings about “sleep 'til noon,” and on “Cinderella” Mac says, “You in my dreams, that's why I sleep all the time,” which Grande later tweeted following his death.

There are a couple other vague hints. Ari sings about not knowing this person would be the one, something “Cinderella” echoes with the line, “You used to tell me all the time I ain't your type." She also references their first kiss, which happened during her music video for “The Way” in 2013, which featured Miller.

That hint led fans to make connections between the whistle sounds in “Imagine” and “The Way,” as BuzzFeed News points out.

The biggest clue might be this response to a fan, where Grande says the song is about "a simple, beautiful love that is now (and forever) unattainable."