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, after accompanying Keith to the big city for Lucy's hearing operation, gets lost. Keith looks for her as Lassie wanders the city, taking in a kid's baseball game, the ocean but then enters an army firing range.

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.