The series follows the story of two young female assassins who embark together on a personal journey to seek answers about mysteries from their past. While they seem to be only vaguely related to each other at first, there are clues and hints given throughout the series that there is more than what meets their eyes. During the course of the series, they are lured into more and more traps by a secret organization named "Les Soldats" ("The Soldiers" in French).