The calm lives of twin sisters Joanna and Alice Conrad are disturbed by the arrival of the worldly Madame Ducreux. What does the alchemist, chemist, and physician plan to do in London and why does she seem to think that Joanna and Alice might spoil her plans? One thing becomes clear early, though: There will be blood before this is over. It's good, then, that neither Joanna nor Alice are shy of spilling a little of it.