by Frederik Pohl
This novella by one of science fiction's greats centers around a struggling merchant vessel's stop at Slowyear, a planet rarely visited by outsiders. When the ship's crew ventures to the surface, they're delighted to find a native agricultural population eager to welcome them and - more importantly - buy their goods. Unfortunately, the hospitable people of Slowyear are hiding a secret, and the crew's profits will come at a terrible price.
Stopping at Slowyear is a subtle, sparsely-written story. Clues to the mystery at its center are so quietly dropped that even some keen-eyed readers will find themselves surprised by the ending. I enjoyed it quite a bit, but it's not exactly typical of Pohl's work and may not be for everyone.
[Spoiler under the cut.]The book's real claim to fame is that it was one of the first fictional stories about prion diseases. Written in 1991, it warned of the dangers of scrapie and BSE several years before the nightmare of Mad Cow Disease ripped through the veil of public consciousness.