When Lassie spectacularly rescues a herd of escaped zebras, a circus director is so impressed by her performance that he insists that Lassie join his troupe. Naturally, he comes up against Zoe's refusal: Lassie is not a circus animal; she is a member of the family. When her beloved Lassie disappears, Zoe is convinced that the circus director is behind the disappearance.