Ciel and Sebastian receive Ciel's aunt: Madame Red, widow of Count Barnett, along with her butler Grell Sutcliff. The season of high society is coming to an end, and London is in an uproar due to murders committed by the one already nicknamed "Jack the Ripper".
Several prostitutes have indeed been massacred under horrific circumstances. Sebastian and Ciel suspect Viscount Druitt is the culprit and devise a scheme to trap him.