Ah, Thalys...
I got caught up in the aftermath of the ICE fire a couple of weeks ago when travelling from Basel to Ottignies in Belgium, a journey that I do about once a month. I missed my ICE connection to Liège in Köln of course, but was just in time for the Thalys that left an hour later. I showed the train manager my DB ticket and asked if I could board, to which he replied: "Yes, but you'll have to buy a new ticket". Not wanting to do this, I decided to follow the advice of the staff on the Basel-Köln train, which was to travel on to Aachen by RegioExpress "where an ICE to Liège and Brussels will be waiting". Except that the RE was 25 minutes late and the ICE had long since left Aachen by the time we arrived.
In the end, after another hour's wait at Aachen, I ended up having to buy a Thalys ticket from there to Liège anyway... and 33 euros for a 20-minute journey is a bit steep to say the least! I eventually arrived at Ottignies four hours late, having been only 80 minutes late at Köln.
My only gripe is with the Thalys staff who, in the exceptional circumstances, could perhaps have been a bit more accommodating with regard to DB tickets.