Songfacts®:

• Trench is set in a world where nine dictatorial bishops control the inhabitants in the walled city of Dema. Twenty One Pilots lead singer Tyler Joseph's alter ego, Clancy, is among those looking to escape. This slow song finds him accepting his role as part of the Banditos, a rebel organization who rescue people trapped in Dema.
  
  I could take the high road
  But I know that I'm goin' low
  I'm a ban - I'm a bandito
  
  Tyler has explained that Clancy tries several time to escape Dema unsuccessfully until he finally makes it out by going underground.
• Tyler Joseph talks in the chorus about how his songwriting and the fictional world he creates has helped him deal with the anxieties and pressures of everyday life.
  
  Sahlo Folina, Sahlo Folina
  I created this world to feel some control
  Destroy it if I want
  So I sing Sahlo Folina, Sahlo Folina, Sahlo
  
  Joseph explained to Coup de Main: "The lyric by itself kind of feels a little cocky or confident, but really, inside of the song, it's a moment where, if anything, it's admitting that the majority of the time you feel like there is no control. I think that's something special inside of creating art, and writing songs, is that you do have control of that - and that has, in a sense, filled me with a sense of purpose, and it's been very helpful for me, and in a way was encouraging other people to do their own version of that, because I've found a lot of strength in building something that is mine, that I have control of in a positive way."
• "Sahlo Folina" is repeated several times throughout the song, serving as a hidden tribute to Twenty One Pilots' origins in Columbus, Ohio. When you unscramble the letters that make up the phrase, you get "all Ohio fans."