Patrick, I believe this is a stand-alone tale, but one with lots of unspoken angst. What were the circumstances of the death of Superman's son? Who killed him, and why? Did he die heroically or tragically? Was Superman somehow involved in the case, and if so, does he blame himself for his son's death? We can reasonably assume that his "wife" is Lois, but we don't really know that. It's barely possible that the circumstances of the son's death split them apart, but we don't know that either, and maybe if they did separate, they later reconciled.
Does the grandson of Superman have any aunts (daughters of Superman)? Will Clark and Lois welcome not only the grandson but his mother into their circle? (I certainly hope so.) Maybe they were planning to marry when the tragedy occurred, and if so, might she have some evidence of this? Will this grandson decide to carry on his grandfather's legacy despite being shunned for the first twenty-odd years of his life?
There are so many possibilities here that I can't count them. But I must credit Mary with being a total and complete genius. This short little offering doesn't have to have any more added to it. The exchange of letters is sufficient. This is truly melancholy and truly beautiful.
