The hungry Forest is moving forward like an army, a green and constant threat to the humans living in and on an increasingly crumbling Wall. Feather, accompanied only by her scaled ferret, Sleek, must avoid the Forest's tentacles, and the many dangerous creatures it shelters, to return the community's precious spyglass to its rightful place. Along the way, she develops her resilience, and meets other people living on the Wall, whose stories and experiences open her mind, and those of her community, to new horizons.