Who Derailed the Guinea Pigs?

The Guinea Pigs are a noisy trio. Their racket annoys their three older neighbors: Turtle, Old Horse and Bobcat. When the Guinea Pigs are the victims of a sabotage, Sherlock concludes that one of the older neighbors must be responsible. At the same time, Sherlock receives a surprise visit from his Ball of Purity. His old master has come to give him a last test that will complete his training.