Human bulldozers are digging up large sections of Parc Montsouris and are getting closer to the mouse village. Pamplemousse encourages the villagers to move, but Anatole thinks they should first find out why the bulldozers are digging so much. The sight of the bulldozers and the destruction they cause, bothers Claude so much that he begins to have fears and nightmares about a dragon (that looks suspiciously like a bulldozer). As half the town pack to leave, Anatole learns that the humans are digging randomly in search of a major underground pipe leak.