Two nuclear missiles
I can’t say anything about this story without spoilers, so here’s the dragon:
There are two types of characters here: workers for a relief agency which rescues people from alternate universes / parallel dimensions, and the refugees. (The refugees are members of a race which I assumed was alien until about halfway through the story, when one offhand comment referred to them as humans). When humans of this race die, their souls are taken into the body of a living member of the race; presumably this is usually a family member and the process works just fine. However, there was a nuclear war which resulted in large numbers of deaths and the survivors being inundated with souls. These soul-laden survivors are dying off, although the story doesn’t specify if this is due to radiation or soul overload; most likely it is soul overload, as there is a child among the refugees who carries no souls, and it is implied that he is expected to live a full life. The only tension in the story is whether this child will ultimately take all the souls from the last adult to die, and once that decision is made, the story is basically over.
The story is a prequel to a novel, The Last Man on Earth Club. In the novel, six men have been rescued from planets on which they were the last survivor. They each faced a different threat (nuclear war, robot uprising, zombie apocalypse, etc.) and were the only one to make it out alive. After reading that part of the blurb, I’m on board; I want this book. Then I read a little further, and learn that the novel follows the six survivors as they participate in group therapy. Now the author has lost me; if I drew a Venn diagram of everything I find interesting vs everything that I imagine happens in group therapy, the circles wouldn’t touch. I was hoping that during the first group therapy meeting, the survivors would lock their therapist in a closet and go off on an adventure to save a 7th planet. The group therapy thing could even work if it were just a wrapper story that allowed the six different apocalypse stories to be told. Unfortunately, a quick browse of the reader reviews at Amazon gave me the distinct impression that the novel really is about the therapy process. I won’t investigate further.