Well, what kind of story do we have here. Not only a plot-twist of a story from the horror cliche of Death literally standing there and just waiting for the time to be right to collect a soul. To the advent of a story that she shall hear very similarly when she meets St. Peter or whomever really is in the afterlife, that of her guaranteed ticket to the Good Life. But let's stop reacting and let's start diagnosing the story:

La filosofía (The philosophy): Well let's fundamentally break apart this story as one would break apart an equation in math. I like to do this metaphysical separation, for that is what it is right now if you are reading this still, and see how yah created the spirit of the post. In the first part, we can definitely see how you employ literally the tropes of Death standing there through the old man, the train entering the tunnel as a sign of going to the Nether/Hell/Heck/Hades and then brought in a malignant evil, cancer, as a mere ploy to give way to randomness of death itself. Yet within the second part these things established get subverted when the old man talks about how she has done good when no one else would that has granted her a ticket to the Good Life post-mortem. For her death wasn't a point of anguish but a point of celebration, her life culminating in the last and ultimate victory; even if cut short, she gets to be high in the clouds now instead of labouring away her life.

La forma (The forma): Now to break down the meta-physicality and treat this post as a dialectical stream. This entire conversation is mediated between the interactions/play-offs between the two. The "unchanging" old man, that may as well be the Angel of Death, who is there to provide the "changing" Joelle a way to the Good Life. The "unchanging" element providing a catalyst to make sense of her last moments in the material realm and show that he, at least the husk that the Angel of Death is wearing is a he, can read into her while providing conversation to comfort her. That's a thing most often left to Science Fiction, Fantasy or Science-Fiction and Fantasy; yet it is carefully woven in her correctly and nicely. I must provide some props for pulling it off... Anywho, congratulations on the @curie upvote!~ (Hope I see you read my entry for this week in the FTS!!!!~)