In 1415's France, Montmorency and his friends Richemont, Charlotte and Philippe are students at a Paris Knights School. However, Montmorency is more interested in alchemic studies, and his dream is to unveil the true power of the Philosophers' Stone that his ancestors bought back from the Holy Land during the last crusade. Meanwhile, France and England are fighting each other during the Hundred Years War, and soon every household serving the King of France is called to arms to protect Paris from the enemy...