Suddenly there is good reason to change trains at Athus, a former steelmaking town in south-east Belgium. There are some small communities around Europe which have over decades assumed mythical status in the high theology of international rail fares. Some of these places are tariff points at or close to frontiers which were important in defining the building blocks which, linked together, allowed agents to sell through rail tickets from London to Athens or Copenhagen to Madrid. Yes, there was a time even in the pre-tech era when such things were possible. Vallorbe and Bellegarde were two such tariff points, both on the French-Swiss border.