I was not sure what this sign meant, but it made me nervous about getting on the train from Istanbul back to Belgrade. Perhaps it meant that my train would be canceled in Sofia two days before I was supposed to fly from Serbia back to the USA, and that the conductor who had asked me to smuggle his favorite brand of cigarettes into Bulgaria would refuse to explain why I needed to buy a new ticket or why the train I was scheduled to be on was returning to Turkey, and that some crazy girls from Germany would try to steal my bunk. Maybe.