While Bonaparte's armies are battering the borders of Europe, the lives of three people from widely differing backgrounds are drawn closer by the war. The beautiful, worldly Antonia is a lady from St Petersburg but what entices her to act as a spy for the British? Why does youthful mathematician Ellen Templeton, raised quietly in a Norfolk village, scheme to locate a diamond necklace that once belonged to Antonia? Lord Matthew Halifax is a very reluctant hero in Wellington's army and finds himself entangled with the exploits of these two strong minded and determined women. But what is the secret that will either destroy the trio or bind them together?