He gave a soft, impressed whistle. "Dimension Door, a card obviously meant to take you Elsewhere. I can believe you'd have to know all the variables, since that's science for you, and magic often works the same way. So, you think the train divides us into teams and gives us team colors as part of a magic spell? I hadn't thought of that, but it makes sense. I wonder what else a card -- or a train -- would have to take into account, besides weight and color?"