Robin can't wait to be back at Fernside boarding school. All she wants is to have fun with her friends in the dorm, play hockey and try to win the Form Shield. But for her younger cousin Linnet the first term at Fernside is a bit of a nightmare. And she needs Robin's help with every little thing. Robin soon discovers that keeping everyone in line is hard. Some of them are even sneaking off to the forbidden garden of Rowanbank. And when the adorable puppy Rudy disappears, can the girls stay out of trouble long enough to solve the mystery?