We were somewhere near the border between France and Belgium when we finally uncorked the warm bottle of rosé. A late-30-something named Thomas—an open can of Cristal Pils Belgian lager in hand—had padded into the train cabin. A French engineer who traveled regularly between Paris and Berlin and cared about his environmental footprint, he was a regular on European Sleeper’s newish overnight route, The Good Night Train, between the two cities. The European Sleeper's Good Night Train offers routes from Paris to Berlin, Brussels to Prague, and Brussels to Milan. I quickly realized that The Good Night Train would be a more utilitarian affair.