The year is 1878, and the spirited Sally Lockhart, once again defying Victorian sensibilities, has gone into business for herself. When one of her clients loses a large sum of money in the unexpected collapse of a British shipping firm, Sally sets out to investigate. But as she delves deeper into the identity of the wealthy and elusive industrialist who owns the doomed company, she uncovers a plot so diabolical that it could eventually destroy the entire civilized world - and if Sally's enemies have their way, she won't live long enough to see it happen.