Madame Toussaint leads the drab life of the concierge in a fashionable building in the glittering Paris of La Belle Epoque in 1895. On a drizzly January morning, the housemaid of the apartment directly over her head runs down to the loge in terror. Monsieur d'Ermenville, the building's owner, has been brutally murdered, and Madame Toussaint and Jeanne-Marie the housemaid are soon in a Les Miserables prison as suspects.

Imprisonment causes flashbacks to the Terrible Year. In 1870-71, Paris endured the Prussian siege, then conquest, then revolt of the Paris Commune which was brutally put down, Frenchman against Frenchman. Madame Toussaint is a survivor of this time when Parisians were reduced to eating rats and died by the tens of thousands. Glittering life and indulgence may have returned to the City of Lights, but under the gilding, hatred and violence linger, living cheek by jowl. The murderer must be another tenant of the building, and all their histories must be uncovered.