After taking part in an unlawful protest demonstration, attractive 28-year-old Anna Dobson is sentenced to 12 months in Blackfriars Grange, a strict Senior Reform School for women. Shortly after arrival, she is introduced to the Draconian regime at the reformatory when she is sent naked to collect her ill-fitting 'school uniform', earning a slippering from Matron in the process. Frequently spanked and humiliated for the slightest of infractions by staff often much younger than herself, it quickly becomes clear that the female wardens take great pleasure in meting out discipline with a variety of implements, including whippy canes, straps and paddles and taking every opportunity to humiliate the inmates. However, it's not only the female staff that Anna has to worry about, as the reformatory receives frequent visits from a middle-aged retired army officer known to all as the Colonel, who takes a positive delight in disciplining the female inmates, an activity he finds extremely stimulating.