When naughty Penny Birch is walking in the woods one day, she is surprised to find a couple pony-carting. Penny is so excited by watching this new form of adult fun that she has to pleasure herself on the spot. Realising how keen she is to discover for herself what it is all about, she begins to investigate this bizarre world of whips and harnesses, of crops and restraints.
Firstly punished by the mysterious pony-girl enthusiasts for misbehaving in the woods, she is soon accepted into their fold after demonstrating her enthusiasm for being made to act in a lewd manner. But will she ever be able to win the highest accolade in their world of kinky games - the honour of being a pony-girl?