Call the Witch

Evan Green just move to the south of Ireland from Canada with his family.
After meet his classmate, the mysterious Fáinne Strange, and have a weird encounter with a stranger in a bookstore of Cork, Woody, Evan's little brother, contracted a rare disease. How to save him from a certain and slow death? Evan will have to find the answer, discovering a world full of witchcraft and supernatural beings, such as the Tuatha De Danann, merrows and ghosts, whose existence he completely ignored. But he wouldn't be alone. Offering his own life, he will make a deal with somebody who will accompany him during his adventure. Only her can help him in this task of death and life.