What leads to the reuniting of the brothers in "Fossil-Figures"? How do they die?

By their fortieth birthday, Edward is creating artwork that is on display in a gallery, and Edgar is indicted on charges of bribe taking. Disgraced, he returns home, welcomed by Edward who knew all along that he would return. When the end came, no one can say, but the brothers are found on the couch in much the same position they were in before their birth.