Hard times came for Carraclough family and they are forced to sell their dog to the rich Duke of Rudling. However, Lassie, the dog, is unwilling to leave the young Carraclough boy and sets out on the long and dangerous journey in order to rejoin him.

Public schoolboy Roddy Berwick is expelled from school when he takes the blame for a friend’s theft and his life falls apart in a series of misadventures.