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.
Lassie's assistance to a toddler is misinterpreted as an attack, and she is chased away from the hospital to become lost in the tangle of city streets; in the meantime Keith searches for her and Elaine wonders what to tell Lucy.
A surgeon gives Lucy and her mother hope that she may hear again after surgery, so Keith and Lassie accompany Elaine and her daughter to Los Angeles for the operation.
Garth's brother Keith is met with resentment when he takes over running the ranch, but he proves his mettle when a storm strikes the ranch and starts a fire that traps Lassie in the woods.