Fully produced by Grimes, her only vocal contribution to this song is the maniacal screams. The rapper you hear is female Taiwanese rhymer Aristophanes, who was spotted by Grimes' boyfriend on SoundCloud.
Aristophanes raps here in the Mandarin dialect of the Chinese language. The hook translates into English as "If you can't scream then swallow it down."
Grimes shot the song's music video with her iPhone while on tour.