A future expedition into the newly uninhabitable areas of Earth near the equator goes terribly wrong. Of course. It's an interesting part of the plot: It's understood that some areas of Earth will become so warm (and humid) that humans won't survive on the surface as global warming continues. But what would that really mean for life on Earth? There's a lot more to this book, principally the unreliable first-person narrator. A perfect novella length.