Seventy-year-old Mag and her forty-year-old virginal daughter, Maureen, live together in Leenane, a small town in Connemara, County Galway. The two women are a constant torment to each other, and Maureen, desperate for a way out of her miserable life, longs to learn of love. Their combative relationship, tempered with a sinister humor, ultimately leads to an unforgivable act of betrayal.