Bondage, discipline and corporal punishment are the key to reforming the character of wayward girls, according to the writings of the fanatical Order of the Righteous Sisters on which Roughton Hall - a remote island reformatory for girls - bases its methods. When Julie is sentenced to three years at Roughton Hall she discovers that total submission is demanded by the sadistic mistresses, who delight in their use of the cane and the birch.
Only the comforting fellowship of the other girls in the dormitory can provide relief from the daily humiliation. After months of degrading punishment the pupils, with Julie as their leader, plot to turn the tables on their oppressors. If their intentions go according to plan, revenge will prove to be sweet.