Sue Ann is a loner who keeps to herself in her quiet Ohio town. One day, she is asked by Maggie, a new teenager in town, to buy some booze for her and her friends, and Sue Ann sees the chance to make some unsuspecting, if younger, friends of her own. She offers the kids the chance to avoid drinking and driving by hanging out in the basement of her home. But there are some house rules: One of the kids has to stay sober. Don’t curse. Never go upstairs. And call her “Ma.” But as Ma’s hospitality starts to curdle 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.