EUROSTAR has got together with its fellow international fast train operators Thalys of Belgium and Deutsche Bahnes ICE to enable customers to travel quickly and easily from the UK to Germany, via a simple connection in Brussels. The alliance means that passengers can now travel between London and Cologne or Aachen with a single ticket. A 24-hour stopover is allowed in Brussels which is the connecting point. Fastest journey time is 4 hours 23 minutes Aachen and 5 hours 2 minutes to Cologne (each one hour less from Ashford International).
http://www.eurostar.com