Jojo and his toddler sister, Kayla, live with their grandparents, Mam and Pop, and the occasional presence of their drug-addicted mother, Leonie, on a farm on the Gulf Coast of Mississippi. Leonie is simultaneously tormented and comforted by visions of her dead brother, which only come to her when she's high; Mam is dying of cancer; and quiet, steady Pop tries to run the household and teach Jojo how to be a man. When the white father of Leonie's children is released from prison, she packs her kids and a friend into her car and sets out across the state for Parchman farm, the Mississippi State Penitentiary, on a journey rife with danger and promise.