1864, under an imaginary Second Empire, Napoléon III uses his army and his secret service to study certain phenomena relating to the occult and to popular legends. His goal is quite simple: achieving world supremacy.
On May 15th, 1864, the special forces of Emperor Napoleon III intervene on the Mexican soil in pursuit of the Republican agent Gavroche. Fearing for his safety, the headquarters of the French Resistance send Églantine on her first mission in the field.
She finds herself under the scrutiny of the fearless Zelda, who's still in the service of American counter-intelligence.