I followed during one routine the ‘Unitat del subsòl’ of the Mossos d’Esquadra (the Catalan police) under the Catalan Parliament inside the subways in Barcelona. This is one of the five special units of the Central Area of Operational Support offering their highly specialized services to other areas of the body of the Autonomous Police of Catalonia. Operates in confined spaces such a subways and sewers, mines, wells, caves, silos, tanks, pipes… Tasks are basically to prevent terrorist attacks and common criminals, but also acts to rescue people, animals or objects.