Last week when the tracklist for the Lorde-curated Hunger Games: Mockingjay soundtrack was announced, one song was left off: the mysteriously unlabeled “Track 5.” (Lorde tweeted that it wasn’t meant to be a mystery and that it just hadn’t been finished yet.) As MTV points out, in a livestream with her fans today, Ariana Grande revealed that she’s the artist behind the song. It’s a collaboration with Lorde and Diplo. “It’s a very interesting song. It’s very different,” she said. To be honest, I’m a little disappointed! I was hoping it would be an original Kanye track or a new Taylor Swift song. Oh well. The Hunger Games: Mockingjay – Part 1 OST is out 11/18 via Republic.