Jess, Mel, Sam, Amber and Cara are lucky enough to be able to spend as much time as they can with their favourite ponies at Vicki's Riding School. Grooming, sweeping the yard, even mucking out is fun when you love ponies as much as they do. It's the start of the long summer holidays, and Sam and her friends are looking forward to spending as much time as they can at the stables. They decide to take part in a fancy dress competition, and work hard making themselves and their ponies look gorgeous. But, as usual, stuck-up Henrietta is determined to spoil their fun. Is dressing up such a good idea after all . . . ?