Ruth and Timmy, visiting the Grand Canyon, befriend a blind pianist with a unique outlook on life who helps Timmy after he is angered by Lassie's behavior when she follows him on a mule ride and he's forced to turn back.

Timmy and Lassie discover the sad truth about Relentless, Cully's new--and much bragged about--dog: he's lost his sense of smell. The truth might have remained secret had not the money earned in a church fundraising drive gone missing.

The Gardners, the Martins' new neighbors, accuse Lassie of killing their cat and attacking their sheep, but Lassie knows there's a strange collie in the area.

Lassie, lonely when Timmy returns to school after a vacation, befriends a raccoon. She is devistated when the raccoon, whom Timmy named Melonhead, is run over by young drag racer Johnny Sexton.