1806, England - When Katherine Wentworth, trained killer known as the Silver Sword, is called to the service of Princess Caroline in London she is apprehensive. Years of training and foreign missions means she has had little experience of society and when she is thrown into the bustling London society of balls and card games in the guise of a lady-in-waiting, she is out of her depth. Adding to her troubles is the charming Mr James Willoughby, who seems to spot Katherine even when she thinks she is hidden. But these are dark times. The assassins are getting closer and enemies are everywhere. Any mistake could cost the life of the Princess. And Katherine will not let that happen.