Straight-laced straight-A student Gemma Codrington likes everything to be neat and well-ordered. She is on her way to university and she takes pride in being good at everything she does. She’s even determined to be very good at sex, if she ever finds the time to have any. But a chance encounter with a mysterious couple at one of her brother’s wild parties makes Gemma realise there are some lessons that can’t be learned from a text book. Under the tutelage of the exotic Lorena and the muscular Gus (together with his “twin brother” Leo) she finds herself juggling studies and sin, discovering that – to get what she needs – a tidy girl must sometimes be prepared to get messy. From dungeons to supermarkets, from buses to back alleys, Gemma is about to learn her most important lesson of all – that the world is full of perils and wonders for a girl with no knickers.