Tyler Joseph via Beats 1:

After I had wrote Blurryface, we really started touring a bunch. Sometimes it’s hard to just start creating. It’s kind of like a muscle, needs to work out. Well, when the “Heathens” thing came up, I kind of took that as an exercise like ‘Let me just get something going. Give me a reason to write right now because I have a lot to say but I just can’t. Everything I turn to, every progression, every sample just feels uninspired to me right now.’ And this idea came up. Well, it’s this movie coming out and I didn’t know much about the movie and, you know, they wanted to know if you’d write a song for it. Like, well, I don’t know. I’ve never done anything like that before. And then they showed me a few scenes and they say, ‘Well, you know, we want you to do either like a shoot-‘em-up Will Smith-like song or a twisted love song between the Joker and Harley Quinn.’ And neither of those things struck me. I was like, ‘You know, I’m just gonna write a song that I feel like is probably gonna be for the next record or at least be for our fans with my own twist on if I were meeting with those villains and I was bringing someone along like ‘Bring Your Friend to Work’ day.’ Well, what kind of conversation would I have in the car before I got in there? In a sense, if this song were to kind of… Well, we kind of got shoved into the mainstream. And I felt like I always wanted to explain to the mainstream audience about our fans and who we really are and try to bring them along and kinda go, ‘Listen. This is what you should expect. You know, tread lightly. But we’re powerful.’ And these kids have something to say and they’re worth listening to. And so that song kind of became something that I wanted to write to explain our dynamic to our fans and thinking that it would in no way fall in line with the movie and it did and it just kind of took off from there. And so, it was a good exercise to get things flowin’ again, a lot of ideas.

The chorus melody was the verse melody ‘cause I just didn’t feel like it was movin’ around the changes like it should and I remember I showed Josh and a couple other guys out on the road when I was just demoing it on my laptop and all I had was the verse and like just the beat and the vibe like, ‘I gotta find a chorus.’ In a few minutes after I showed them, we’re gettin’ ready for the show and I hear someone. I still don’t know who it was. It was one of the four or five guys that I was kind of just showin’ stuff to. They whistled the melody of what I thought was the verse down the hall as I was gettin’ ready. And that’s when I was like, ‘That’s the chorus.’