Ten-year-old Philip Ransome (Mark Lester) has been almost entirely mute since the age of four. Unable to connect to his parents, he spends his days wandering the moors alone. One day, he meets an albino horse and immediately becomes attached to it. Later, he befriends a retired colonel (John Mills) and a girl his age named Diana (Fiona Fullerton), who helps him train a falcon named Lady. Philip slowly begins to emerge from his shell, but every time he seems to be making progress, something happens to set him back.
Run Wild, Run Free contains examples of:
- Ambiguous Disorder: It's never explained why Philip went mute. Time Magazine's review refers to him as autistic, which would make Run Wild, Run Free possibly the first ever autism movie, although his symptoms seem more like selective mutism.
- And Starring: "And Mark Lester as Philip Ransome, also starring Gordon Jackson and Fiona Fullerton."
- Commonality Connection: The Colonel speculates that Philip's attachment to the horse might be because they're both different from the others - the horse because of his albinism, Philip because of his muteness.
- Fantasy-Forbidding Mother: Briefly - Philip's mother locks him in his room because she thinks his wanderings are dangerous and his attachment to the white horse is unhealthy, but she lets him out when she sees how miserable he is.
- First Friend: Philip wasn't close to any other human beings before he met the Colonel.
- Free-Range Children: At the beginning of the movie, Philip attends a clinic for emotionally disturbed children, but his mother stops taking him because she doesn't think it's helping. For the rest of the movie, Philip is free to spend all his time on the moors.
- Freeze-Frame Ending: The movie ends on a close-up of Philip's face.
- The Grand Hunt: A group of hunters on horseback appears twice with their pack of baying dogs. In their first appearance, they spook Lady, who tries to fly away. Her injured wing can't support her, and she is killed. Later on, they startle the horse into running away into the bog with Philip on his back.
- Horsing Around: Philip gets thrown off the horse's back a lot before he and the Colonel tame him.
- A Minor Kidroduction: The earliest scenes show Philip as a toddler.
- Nature Hero: Philip feels a deep connection with nature. He's been trying to explore the moors since he could walk, and before he went mute he knew the name of every plant and animal he saw.
- No Name Given: The Colonel is credited as "The Moorman."
- Say My Name: A lot of Ellen Ransome's dialogue consists of yelling "Philip? Philip!"
- Scenery Porn: The movie is full of shots of the beautiful moorland.
- Take My Hand: At the end of the movie, after Philip has succeeded in rescuing the horse from the bog where he was trapped, his parents take his hands and pull him to safety.
- What the Hell, Hero?: Diana and her uncle Reg both yell at Philip after he tries to run after the white horse with Lady tied to his wrist, breaking Lady's wing.