Затерянный прииск

Given its concise length, I'm curious whether this story was based on a real event or purely fictional imagination. What do you think led her to this plot?

The ending wrapped up neatly, but I wondered if that was intentional or just the way Christie preferred to conclude her mysteries. What was your take?

The backdrop of a remote mine gives the story a rugged, isolated feel. I wonder if Christie chose this to heighten the suspense or for other reasons.