London 1885. A gang of lady thieves is targeting Piccadilly’s wealthy shoppers and no one seems able to stop them. As frustrations build, the body of a young woman is pulled from the River Thames. Reporter Penny Green has a lot to write about, and she faces a new challenge when a stranger approaches her with a riddle. Could it lead to a killer?

Time is running out for Penny - her impending marriage to Inspector Blakely signals the end of her Fleet Street career. The riddle could be the last case she works on and it's not without its dangers. Someone seems keen to ensure that Penny doesn't make it to her wedding day at all.