Is this the film that I am thinking of? (may contain spoilers)

There was a Scandinavian film that I saw part of several years ago, that I have wanted to see in its entirety, and I am not certain if this is it. As such, this post may or may not contain spoilers. I do not remember very much of the part of the film that I did see--a character either sets or attempts to set a fire in a building, there some kind of conflict surrounding a family business, and two characters have a relationship that is either incestuous or at least somehow predicated upon the connection of one to the family of the other. I apologize in advance if this is not the film I am thinking of, and in that case I would greatly appreciate someone letting me know what film I am thinking of.