Atalanta, the boss of an organization in the underworld of the Empire that was notorious against nobles. One day, she receives a request from the emperor to assassinate the tyrant Archduke Lionel Bianque. Atalanta, who wanted to live a normal life with her gang members, accepted his request. She infiltrates the Great Siege and attempts an assassination attempt... . But why don’t you die? Can Atalanta safely escape from the Grand Duke who whispers love in an instant?