In Edinburgh in 1860, sheep herder Jock Gray finds a Collie puppy on the loose. When she is unclaimed, he takes her as his own and calls her Lassie. They are soon inseparable but when Jock dies and is buried in an unmarked grave, Lassie takes to sleeping in the churchyard to be near him. Jock's good friend John Traill is prepared to find a good home for Lassie but no matter how hard he tries, she always manages to get away and despite any obstacles put in her way, manages to get back to Jock's grave. It all comes to a head when a local magistrate orders her destroyed for not having a license leading Traill to take his case to a higher court.