It's the eve of World War II, and miner Sam Carraclough (John Lynch) is out of a job. He and his wife, Sarah (
Samantha Morton), must keep food on the table, so they make the painful decision to sell their beloved dog, Lassie, to the Duke of Rudling (
Peter O'Toole), who will give the collie to his granddaughter, Priscilla (Hester Odgers). The Carracloughs' young son, Joe (Jonathan Mason), is heartbroken when he gets home and Lassie's gone. Lassie escapes from the duke's kennel several times, so he ships her off to his remote castle. But she's determined to return home, and, with Priscilla's help, Lassie manages to get through the gate, setting off on a cross-country adventure that has her seeing the Loch Ness monster, escaping from a dog pound, and falling in with a traveling puppeteer (
Peter Dinklage).