Murder most familiar

Hugh Mason was the kind of man it was very easy to hate, if you were not susceptible to his particular kind of charm. He had of necessity hurt a lot of people on his way up. Taciturn and enigmatic, his extended family did not really know him well. At a weekend gathering for his 60th birthday, it slowly becomes apparent that Hugh plans to give substantial funding and support to a new right-wing political group called the Freemen. The next morning Hugh is dead of poisoning and the evidence suggests a family member must be responsible. But who among them would risk such a move, given that Hugh provides for all?