In the wake of the Dreyfus affair, two murders reveal the darker side of human nature. After an infant boy is found dead in the town of Nancy in historical Lorraine, France, and the townspeople, thinking a Jew was responsible for the murder, whip up a frenzy of anti-Semitism, it is up to Bernard Martin to find the true killer before a vigilante mob embarks on a spree of racial violence.

Bernard and Clarie Martin are on the case after two young women disappear after having assisted a Russian man throw a dead body into a canal in 1897 Paris.