Sylvia "Vivi" Hayden is one of the best assassins in the old London (18th). Strange things happen that leads to events where Vivi must fight not to break one or all of the three rules of an assassin, 1. Kill or be killed, 2. Never go into rage, 3. Never fall in love. But nothing is easy when the streets of London are filled with traitors, plots and ever lasting secrets.