A young girl named Lorna is kidnapped from her mother by a marauding group of thugs called the Doones. Years late the girl has grown up into an attractive young woman who is under the tutelage of Sir Ensor Doone - an aging ex-Nobleman who has become her father figure. He protects her and refuses to allow anyone to marry her whom she finds objectionable, which turns out to most of the thieves and cutthroats that make up the clan. In particular is Carver Doone, a mean-spirited brute who drinks, curses and fights a lot as a way to impress Lorna.
One day Lorna (Madge Bellamy) is out by the river and she comes across John Ridd (John Bowers) an old acquaintance who she met as a child right before she was kidnapped. They quickly strike up a conversation and it's obvious they are made for each other. He leaves before trouble starts but it's obvious he will be back.
John eventually finds his way to save her from the madness of Carver Doone who is determined to marry Lorna as soon as Ensor dies. When Ensor does die John takes her back to his modest farm. But she learns that Ensor has made her a Lady of the court of England, which she cannot turn down. John is sad but lets her go.
Eventually they will meet again but not before a couple good action chase scenes and fights with the evil Doones ensue.
The film clocks in at 87 minutes but it doesn't move that fast. There is much histrionic acting and some slow bits and director Maurice Tourneur paints in broad strokes: Lorna and John are very innocent while Carver is the obvious villain. The one character with any shade of good and bad is John's cousin who secretly loves him and plans to ruin their wedding day.
What the film is good at is atmosphere and visuals. Mostly shot in a sepia tone the film has a classic literary look. It is also unintentionally humorous; twice John Ridd falls off a 100 foot waterfall [the first on accident, the second time on purpose. It seems the quickest way to get into the Doone valley]. Lorna's frightened look is over-the-top, John stands around with a blank look a lot and some of the fight scenes have a staged quality that undermines their power.
Overall, the film is good if not a bit underwhelming. The musical score - on the other hand - by Mari Iijima is very good and gives the film life when it needs it most.