The train is a long series of uncertainties. Which cars are going to be leaving? Which one will take you to Medias Aguas and which to Arriaga? How soon will it leave? How will you duck any rail workers? To avoid an assault, is it better to ride the middle or the back cars? What sounds signal you to jump on? When do you get off? What happens when you need to sleep? Where is the best place to tie yourself to the roof? How do you know if an ambush is coming?