When a public tragedy threatens to expose a scandal within the Paris government, the Minister of Public Works calls in a favour to Maigret.
A public project has collapsed and resulted in the death of 128 children after a report warning officials about the unsafe structure was disregarded. Now, that report has resurfaced, along with allegations that several politicians and contractors involved with the project may have suppressed its findings to avoid a scandal.
Maigret must enter the shifty world of politics, dogged by members of the security police wherever he goes. In an unfamiliar world of decadent diplomatic officials, fanatic followers of political parties and suspicious staff in politicians' entourages, Maigret grimly sticks to what he knows best: finding the perpetrators of criminal acts.