Halloween comes to life.

Mathilde, a marginalized teenager, must move to the countryside with her family for a reason she would like to bury deep inside herself. Upon moving into her new home, she discovers that a ghost lives there. This ghost is that of Isabeau, a very friendly and sympathetic 19th-century woman who has modernized over her 150 years of wandering. These two characters will become friends and help each other through (one) life and (the other) death. While unraveling the injustices they have experienced, rooted in their respective eras, they develop deep bonds that will allow them to find peace.