It is 1968. Lynnie, a young white woman with a developmental disability, and Homan, an African American deaf man, are locked away in an institution, the School for the Incurable and Feebleminded, and have been left to languish, forgotten. Deeply in love, they escape, and find refuge in the farmhouse of Martha, a retired schoolteacher and widow. But the couple is not alone-Lynnie has just given birth to a baby girl.

When the authorities catch up to them that same night, Homan escapes into the darkness, and Lynnie is caught. But before she is forced back into the institution, she whispers two words to Martha: "Hide her." And so begins the 40-year epic journey of Lynnie, Homan, Martha, and baby Julia-lives divided by seemingly insurmountable obstacles, yet drawn together by a secret pact and extraordinary love.