Disaster strikes at Meadow Vale Stables! Horse thieves have come in the middle of the night and stolen Sam's pony, Mulberry. Horses, Velvet and Lucy, are missing too, and no one knows if any of them will ever be seen again. The horses are taken to a rundown farm and locked up in dirty stables, watched over by a sly cat. Clever Mulberry escapes, but who is going to believe that Sam can talk to Mulberry and knows where the horse thieves are hiding? With Sam riding Mulberry bareback, they set out on the rescue mission alone - alone except for the mischievous Shetland ponies who don't want to be left out of the excitement! But when they get there, it's not just the ponies who need rescuing - a pair of surprisingly cuddly ferrets need their help too. Can Sam and Mulberry save Velvet and the other animals before it's too late? A funny, heart-warming story about a girl and her very mischievous pony.