Shaken by the violence of climatic conditions, the extinction of thousands of species and the depletion of its resources, the Earth is crying out in alarm. Faced with this distress and in a last hope of survival, humans establish new social arrangements. If America sees bloody purges, Europe announces the creation of the Systra law.
Callie is born in this world. An intelligent girl, loved by her parents, her destiny changed with the arrival of her forbidden little sister, Kaya. Thus, the Systra law is applied: the children will be separated, raised far from their parents, according to very different customs, only to meet again a few years later: the day when they will have to face each other.
Only one must remain. The other must disappear. Forever