In 1349, Eifelheim, a small town in the Black Forest of Germany, vanished: it ceased to appear on any maps or in any documents, having apparently been abandoned and never resettled by its community. The disappearance is no mystery — the Black Death devastated Europe. But why was the area never resettled, unlike most other depopulated areas? The mystery intrigues cliometric historian Tom Schwoerin, who sets out to solve the puzzle with the help of his partner, theoretical physicist Sharon Nagy. They gradually uncover evidence of an alien crash-landing in the area.