I planned to GM this story and I would like to get some advices.
First : do you plan to add the map of the main village/town or, by default, a "typical" map of a sweden village/town that could help the beginner GM ? Knowing weather conditions in winter in Sweden, I guess that there is some specificities that won't work for other villages/towns. I was thinking of Twin Peak town (http://welcometotwinpeaks.com/) or Ichor Falls town (http://broodhollow.wikia.com/wiki/Ichor ... or's_Guide).
Second : Is the town big enough to get its temporary fairgrounds (for example : http://www.washcofair.com/images/midway2.jpg ) ? I could use this kind of artefact to amuse children with something that could become a normal event and make them believe that the mystery will be there this time... And it could become a hook for other times !
As a french GM, I hope everything is clear. I will update this post later, after some research for the right words.