The Devouring Gray by Christine Lynn Herman

On the edge of town a beast haunts the woods, trapped in the Gray, its bonds loosening…

Uprooted from the city, Violet Saunders doesn’t have much hope of fitting in at her new school in Four Paths, a town almost buried in the woodlands of rural New York. The fact that she’s descended from one of the town’s founders doesn’t help much, either—her new neighbours treat her with distant respect, and something very like fear. When she meets Justin, May, Isaac, and Harper, all children of founder families, and sees the otherworldly destruction they can wreak, she starts to wonder if the townsfolk are right to be afraid.

When bodies start to appear in the woods, the locals become downright hostile. Can the teenagers solve the mystery of Four Paths, and their own part in it, before another calamity strikes?