Used book – Le souffle de la hyène, Pierre Bottero

Natan lives in Canada and excels at all sports, to an uncanny degree. Shaé lives near Marseille. She possesses, lurking deep within her, a Thing she cannot control. When they meet in Marseille, they realize their lives are intertwined...

After escaping faceless individuals and infernal creatures, they are taken in by Natan's family and enter the House of Elsewhere. But the Other, a triple and terrifying incarnation of Evil, hunts them there...

A fast-paced fantasy story served by rich writing and constant inventiveness. Two teenage heroes discover their heritage, both fascinating and dangerous, and the weight of their responsibilities: Natan is confronted with the sudden disappearance of his parents, while Shaé tries to tame a power that questions her identity.