“Trees” is the oldest song written for Vessel. twenty one pilots recorded it for their independently released 2011 album Regional at Best and then rerecorded it for Vessel after they signed under label Fueled by Ramen. As Tyler Joseph explains in an interview, the original lyrics were inspired by an event in his life in which he was searching for something in the woods. The ultimate message he explains, is a search for truth.

What form this truth takes on is up for debate. There are two general interpretations of these lyrics:

• A chance encounter occurs in a the secluded forest between two people who suffer from social anxiety. They nervously wait it out, not saying a thing.
• A spiritual journey is depicted in which the narrator feels as though he has found God but struggles with doubt, as God doesn't show Himself directly.