A little behind here. I've been puzzling what to do for the next Fortnightly Book, and I've decided to do a re-read: Michael Flynn's Eifelheim. It is based on a novella originally published in Analog Science Fiction and Fact in 1986, and the novel itself was published in 2006. So later this year (October for the novella, November for the novel) it will be forty years since the original novella and twenty since the novel itself was published, which seems to make this a good time to do it.
This will be the third Flynn novel I've done for the Fortnighly Book, and I have in fact been intending to do it for some years now. As was the case with In the Country of the Blind, the novel has a frame at a different time; in that book the modern story was the primary tale, and the frame was the backstory. In this work, however, the main story is a medieval tale, and the frame is a modern frame about some of the consequences.
In the fourteenth century, without any clear reason, the town of Eifelheim in the Black Forest seems simply to have vanished, and the entire area becomes associated with strange events in devilry. The disappearance alone could be explained by plague or something similar; but one would expect from other cases, given its location, that it would be resettled, and a general cause doesn't explain the specific associations. Something strange happened in Eifelheim in the fourteenth century, something so momentous that it will have significant effects even when it is rediscovered in our day: Aliens crashed nearby. But the story itself is more complicated....