It's not the first time Frances Burnett and her friends have had to search the moor for a lost horse and rider. This one is different; the horse has been seen on the moor, tacked up but with no rider. Some people are convinced the horse is a ghost, wandering the moor looking for its lost master.

Dr Burnett is far more worried about the horse's rider, possibly lying wounded out there on the moor. Frances and Louisa agree to help, wondering if they're wasting their time over a horse that doesn't actually exist. And Frances is beginning to realise that she likes Felix Hamilton, their friend, but he is spending all his time with the glamorous and wealthy Natasha.

Will they find the ghost horse? And its rider? And will Frances overcome her jealousy of Natasha?