“¿” marks the first collaboration from Bring Me The Horizon and Halsey. In the track, Halsey sings of a relationship turned sour, haunting her like a bad dream.

Bring Me The Horizon alluded to possible collaboration with Halsey in an interview for ENTERCOM in February 2019.

The collaboration rumors were further flamed after Oliver posted a picture on Instagram of himself and Halsey in July 2019. That same day he also shared a video of Halsey singing an unknown song to his Instagram story, which is still unreleased. Another song was released as “Experiment On Me” on February 7, 2020.