The mysterious dog showed up at Jax's door just when she needed an adventure. But adventure sometimes brings trouble -- and dangers that even a great dog can't help you escape. In the Catskill Mountains, mystery is waiting . . . . Just when she needs it most, a little excitement comes to Jax's mountain. First, a beautiful, giant dog stops at her door. Even though he has no collar, the Tibetan mastiff doesn't act like a stray -- and he...