Just like MAGIC (tm), a family of four comes sprinting down the street, leaps over the exit gates, and proceeds to board the moving train.
"NO, NO, NO!" I shout, as I run down the platform at (my) full speed. Apparently, I'm pretty good at shouting no, as the sight of this gray-haired, fat conductor running toward them frightens them enough that they all jump back over the exit gates.
With them safely out of the way, the engineer whistles off again and the train chugs into the night.
"What exactly is your problem?" they demand to know. "We weren't going to hurt your train!"
Somehow, I had never considered that a collision between a 100-ton train and a guest might hurt the train....