The heroes met Dieter Heikkenen in Eisen while they were on the trail of Wolfgang von Drachen. When they explained the situation to him he was able to provide them with a set of manacled, Dracheneisen gauntlets - something which even Zerstorung would be unable to break free from.
In return, when the heroes confronted and apprehended Wolfgang von Drachen, Dieter Heikkenen arrived to claim the prisoner and return him to the lands of Stefan Heilgrund - presumably to undergo trial and sentencing.