Timmy and Boomer are heartbroken when they find out Lassie's puppies are to be sold, so Lassie hides them in an old pen in the woods. But the mischevious babies get free.

Jerry, the lame boy who adopted Lassie's son Blacktail, and his dog visit the farm, when the Martins find out Jerry can walk without his brace, but is afraid to try.