The Moon Stallion 1978 Directed by Dorothea Brooking
A young girl named Diana, her archeologist father and her brother visit friends in Berkshire near the site of the ancient Celtic horse cut into a chalky hillside. Though Diana is blind, she has the "sight" which connects her to a mysterious white stallion, to an ancient legend of Arthur as a Celtic chieftain, and to danger from others who seek paranormal power.
