2 April 1879, St Petersburg. A shot rings out in Palace Square. The Tsar is unhurt, but badly shaken. Cossack guards tackle the would-be assassin to the ground. And in the melee no one notices a pretty, dark-haired young woman in a heavy coat walk purposefully away from the scene. Russia is alive with revolutionaries and this is just one of many assassination attempts on the unpopular Tsar Alex...