The fourth book in Janet Rising's fun and fresh new horse series featuring a girl that can talk to horses-and an irreverent, sarcastic pony that talks right back! Pia and her friend Bean win an exciting riding vacation. But when things start to go missing around the riding center, Pia is shocked to hear what the ponies have to say! Meanwhile back at home, Katy falls sick, and there is only one other person who can take care of Drummer while Pia is away. And this person happens to be Pia's worst enemy...