We were all on the train when the world ended.
There's twelve of us now, but there used to be more; some let themselves fade away, or set out on a different path, or just died from something or other. Just because the apocalypse is surreal and magical doesn't mean death always is, after all.
We're the ones left because we were all looking for something, I think. Cindy wants to see what happened to her old college, Matthias wants to see the ocean by their home again...all of us have something anchoring us here, something that won't let us fade away.
It might sound silly, but I think that's why the train is still here, too. She was all shiny and new when we boarded her, out on her first real journey, her first time carrying passengers. And so, like us, her unfinished business saved her.
Her duty is to take her people to where they need to go. She won't be stopped from carrying it out, either; not by impossible wreckages of earth and air where no tracks lead, nor by dreamlike wastelands that beckon us to fade away and abandon the remains of this world; for she is iron and lightning, and she is far stronger than that.
She will carry us until none of us remain for her to carry.
That last line carries a really special vibe