Everybody's welcome at Ma's. But good luck getting home safe. Sue Ann (Oscar winner Octavia Spencer) is a lonely woman who keeps to herself in a quiet Ohio town. When a local teenage girl asks Sue Ann to buy some booze for her group of friends, she decides to make some new friends of her own and offers her basement for the kids to party. They just have to follow a few simple house rules: Someone has to stay sober. Don't curse. Never go upstairs. And call her "Ma." As Ma's hospitality curdles into obsession, what began as a teenage dream turns into a terrorizing nightmare, and Ma's place goes from the best place in town to the worst place on earth.