Ettie has lived blissfully with just her grandma for company and the wild woods as her playground. Until she meets the mysterious Cora and she starts to crave more - now she wants to explore further, to discover secrets of her own. So, when Cora leads her to the hidden quarry pool - deep, cold, beautiful and dangerously inviting - Ettie is ready to jump straight in. But the quarry has secrets too, and Ettie will have to dive deep into the darkness to uncover them . . .