The Grey Heart: The Zone Awakens٨. Book 1: The Zone Awakens, #1

In the town of Fellbrook, every child who turns thirteen disappears for one night into the Grey Zone - a world that feeds on your deepest fears and sends you back forever changed. Lena Voss enters the Zone carrying a heavy secret: she is convinced she is the reason her mother died six years ago. But inside the Zone, she discovers the terrifying truth: her mother never died, but became part of this world.
Now Lena begins to transform into something not fully human, and she must face a dangerous secret organization and an ancient, hungry entity. or try to save it. A dark, emotional, and deeply moving story about forgiveness, friendship, and the courage to confront your fears.