Under the cover of night, 12-year-old Homer flees Southerland Plantation with his little sister Ada, unwillingly leaving their beloved mother behind. Much as he adores her and fears for her life, Homer knows there's no turning back, not with the overseer on their trail. Through tangled vines, secret doorways, and over a sky bridge, the two find a secret community called Freewater, deep in the swamp. In this society created by formerly enslaved people and some freeborn children, Homer finds new friends, almost forgetting where he came from. But when he learns of a threat that could destroy Freewater, he crafts a plan to find his mother and help his new home.