Our Saint-Josse spring has its source underground. The novel by Tijl Nuyts, originally from Schaerbeek and winner of the Boon Literary Prize, also takes place in the underground of Brussels. We sat down together on the square to dissect his book, in a friendly atmosphere, sitting under a tree on this summer evening. "Grondwerk" reveals a world hidden under the Place de la Patrie in Brussels. Hidden in a network of galleries, a naked mole-rat, on a mission from the Horn of Africa, awaits a briefing. A man who appears at its burrow gains its trust and writes down its story word for word. Meanwhile, sinkholes are appearing all over the city. Something is brewing at the administrative heart of Europe. Is a revolt being prepared? Grondwerk is a story of resistance and reconstruction, of collective action, of shared land, and of attempts to make the world habitable. A novel full of conspiracy theories and visions of the future, which shows that we cannot do without each other.