In an alternate early 20th century, the discovery of Cavorite leads to advanced military technology and a nation on the brink of war. London is now divided by a wall, with the Kingdom and the Commonwealth of Albion engaged in a covert battle reliant on espionage. A secret group of girls from Queen's Mayfaire school serves as undercover spies for the Commonwealth. Under the leadership of Dorothy, a charismatic driver, the team includes Ange le Carré, a skilled sharpshooter and deceiver; Chise, a masterful samurai; and Beatrice, a talented mimic. With each member's unique abilities, they navigate a world of secrets and infiltration to aid the Commonwealth amidst a backdrop of conspiracy and uncertainty. United by a singular purpose, they strive to fulfill their mission under the looming shadow of war.