Hoping to help his self-esteem, Garth takes Jimmy back to the ranch with him. There the uncertain boy meets Lucy Baker, a girl who's been deaf most of her life, and her pet wolf Mountie. But while Jimmy and Lucy get to know each other, Mountie, playing with Lassie, is shot by a shepherd who doesn't know he's a pet.

After Lucy and Jimmy find Mountie in the cave where Lassie has hidden him, Lucy sends Jimmy for help on her horse. He is frightened to do so, but does so for her sake, and despite being thrown, finds Domenic, the shepherd who shot Mounty. Meanwhile, Lassie returns to the ranch.

When Mountie weakens and then dies, even normally optimistic Lucy cannot understand and sinks into depression, so Sue asks her to help out at the wild animal park to take her mind off her loss. Eventually Lucy begins taking an interest in the animals, including a llama about to give birth.

A crow that snatches Mike's wallet leaves the boy angry and determined to find the animal.

A small deaf boy is found wandering the grounds of the ranch and Lucy, communicating with him in sign language, discovers he feels no one wants him.

Lassie befriends a racehorse so nervous that he can't complete a race.

A runaway inner-city orphan is taken in at the ranch, but is distrustful of everyone.

Keith accompanies Lucy and Elaine into the city for tests with Lassie going along. Lucy turns out to be a candidate for surgery to restore her hearing but during the operation Lassie wanders off.

Lassie continues her journey home, getting a fish hook in her paw before being helped by Jim and his surfer friend. Accepting a ride north with his two new pals he nears the Holden Ranch. Lucy finds out if her hearing operation was a success.

Lassie, after a narrow escape on a firing range, befriends two young men who have been camping at the beach in their van. While they tend the injured collie, Lucy, now returned home, prays for two miracles: that her hearing -- and Lassie -- will return.