Has Fifty Shades of Grey really transformed us from a nation of prudes to one of happy spankers? It may have brought bondage into the mainstream, but are the British really ready to embrace sexual experimentation? From visiting a spanking class, where novices are trained in the art of a good caning, to exploring the world of an S&M couple who have written sex contracts with each other, this documentary uncovers what the erotic paperback phenomenon tells us about 21st-century Britain. The programme examines the sociological and cultural effects the book is having in the UK, as sales of obscure classical music and bondage gear increase. A book club from North Yorkshire read the bestseller for the very first time and share their verdict, while adult retailers Ann Summers reveal what steps they are taking to exploit this trend. Psychologist and sex columnist Pamela Stephenson and Brooke Magnanti, who wrote Belle De Jour, share their reactions to the Fifty Shades of Grey phenomenon. The book has crossed continents, class barriers and the context in which porn is read - on the train, in book groups and even at the hairdresser.