The Stillwater Girls

Wren and Sage have been left to fend for themselves in their isolated, off-the-grid, primitive cabin in upstate New York after their mother leaves with their sick younger sister to get help from the nearest town. As the months pass their hope vanishes when a stranger comes. The stranger claims to be looking for the girls' mother, and he won't leave without them. The sisters break the rule to never go beyond the forest in order to escape. But once on the other side the sisters must confront what has been hidden from them, and what they're running from. -- adapted from book jacket