Alison is told to become [Queen] Margarita's knight.
In this era, there is a group of people who are born into slavery, and their souls are branded with the blood mark of obedience; while there is another group of people who are unfortunately played by fate and forced to submit to the royal power.
When Alison falls under Margarita's wing, she gains power, but that doesn't seem to be a good thing.
When reality and dreams become confused, Alison can only trust herself.