Paris has been thrown into mourning after a fireworks display for the Dauphin?s marriage to Marie Antoinette has been disastrously mismanaged, and a conflagration has led to panicking crowds and carnage. Hundreds of people have been injured in the mêlée, and many have been crushed to death. Watching the conflagration (at first, from a distance) is the youthful Commissioner Le Floch, who has already calculated that things have been badly planned, and attempts (in vain) to aid the victims of the catastrophe. But one of the deaths on that fateful evening has nothing to do with the fireworks: a young woman has been found strangled amongst the many other corpses. Nicolas is given the assignment of tracking down just how the young woman died, but he has, in fact, another agenda -- one that involves nothing less than corruption and skulduggery in the upper echelons of state power.