Nous sommes au 19e siècle dans la ville de Londres qui est située dans le Royaume d'Albion. L'est et l'ouest du Royaume sont séparés par un mur. C'est dans ce contexte que cinq jeunes espionnes s'infiltrent dans la ville en se faisant passer pour des étudiantes de la prestigieuse école Queen's Mayfair.

Ange has just transferred into Queen's Mayfaire Academy, and she's on a mission to recruit the Princess. The only thing standing in her way is the Princess' agenda.

The connection between Ange and the princess comes to light, and the girls discover Beatrice's extraordinary talents.

The girls are sent to retrieve a certain prototype from the Kingdom. In the meantime, Dorothy must keep a close eye on a friend.

The Princess must host Lord Horikawa during his time in the Kingdom of Albion. Only to be met with assassination attempts directed towards them both!

Dorothy must take a case that involves her father, to retrieve a something from a dead body at his morgue. Does this bring them back closer together?

The girls have their next assignment, and they must infiltrate a laundry mill to find a deadly weapon. In the mill, they catch a glimpse of the workers' conditions.

As Ange is painting, she is reminded of the first time she met the princess. With fiction and reality clashing, Ange questions herself.

Chise writes to her sister about her life in the Kingdom of Albion, and how she struggles to adapt to their customs but the girls try their best to make Chise feel at home.

Control gives Ange and Dorothy a new assignment along with an old acquaintance. Unfortunately, old memories arise that can't be swept away.

Ange must now fulfill her newest orders: assassinate the princess. With outside forces starting to make their move, what will happen to the Princess and Ange?

With time against her, Ange will stop at nothing until she has the princess next to her. Will she be too late to save her?