I'm not a huge George R. R. Martin fan, but I've read some of his stuff and generally liked it, so a free short story was certainly worth listening to.
Basically, this is an alien colony world mystery, the mystery being the "wraiths" that supposedly inhabit Wraithworld. The planet is shrouded in mists and mostly unexplored, and a few mysterious deaths had made it something of a tourist attraction for thrill-seekers. Then comes a scientific expedition to settle the question of the wraiths once and for all. The owner of the planet's main hotel doesn't want the wraiths "discovered."
Unfortunately, the tension between the scientist and the hotel owner never produces much more than a philosophical debate rehashing the old "Should we know everything, or should we leave some corners of the universe unexplored?" debate. The journalist who covers the story seems almost superfluous.
This wasn't a bad story and it's worth the 40 minutes it will take to listen to it, but it's not a sci-fi landmark or anything. Good if you like SF short stories or GRRM, and you can't go wrong with free.