I am going somewhere in the train.  I have to board a train - transfer from one to another.  It is one of those whistle stops where the train only stops for a few seconds, and as I am running from one to another one of my sandals falls off by the train I am leaving.  This happens either once or twice, but when I run frantically back to get it, my legs will hardly move.  The train depot is a modern, air-conditioned glass building.