When Sadie, a kindergartner, suddenly turns into a frisky leopard cub, her mother and brothers take her to a doctor, a veterinarian, and even a zoo seeking a cure.

Twelve-year-old Maggie's stutter causes her much heartache and only her menagerie of pets, whom she can speak with fluidly, provide her comfort, but when she finds Rumpus, an abandoned snow leopard in a forest in Cornwall, their chance encounter will change their lives forever.

The magic tree house is back with a message from Morgan le Fay telling Jack and Annie to seek out "The Gray Ghost" and listen to her story, and immediately they are whisked away to Nepal where they meet Tenzin, a climber who has recently lost his family, and who takes them up the mountain to meet a snow leopard and renew himself.