In this exciting sequel to "If Horses Were Wishes", Katy's adventures continue in her guise as Lady, the horse who makes up the sixth part of a detecting gang of friends. The suspense runs high as the Fallon Five are determined to get to the bottom of some very strange goings on in the large stable yard of their mortal rival in the show jumping arena. Katy has to use every ounce of her strength and the skills she has only recently learned, to smuggle herself into the yard as an undercover horse-spy. But she discovers the stakes are much higher than any of them had expected - and that their foes are armed, dangerous, and very angry.

With the help of the horses in the yard, and then from a surprisingly unexpected quarter, the Fallon Five cause mayhem in their quest, and finally succeed in finding out what they've come for. But will the friends be able to make it home safely and persuade the adults that they are telling the truth about what they have found? Will they be able to save the remaining horses at the stable yard? And will Katy remain happy in her new life as a horse, or will she finally decide to try and turn back into a girl?