The Midwich Cuckoos/Le village des damnés
Suggestion proposed by M. Miller in this comment. In John Wyndham’s science fiction novel, The Midwich Cuckoos, 1957 (later filmed as The Village of the Damned, 1960) a circular line is plotted on a map to determine the area around the village of Midwich in which people are mysteriously falling unconscious. One watching private stepped forward…