This is The 1946 Little Teacher Containment Operation in Joachimsthal, Czechoslovakia by Sascha Schmidt, a mythical creature horror story set in a post-war Sudetenland refugee camp. When infants begin dying with grey palms and black fingernails in a camp beneath a hydroelectric dam, black marketeer Antonín Kovář recognizes the symptoms from his sister's death in 1923. The knocking in the turbine foundations is not mechanical failure or German sabotage—it is an ancient subsurface species declaring territorial boundaries through the karst stone, and the dam has been built directly inside its cognitive network.

Recovered field notes and classified reports reveal a biological reality older than the mines: the entity extends its mind through cave systems, searches for organic compounds on the surface, and leaves arsenical deposits letha ...