Determined to educate the town's illiterate children, spinster schoolteacher L.C. Moffat opens a school in the tiny Welsh coal-mining community of Glansarno. Battling the contrary local squire. Miss Moffat becomes increasingly discouraged until she sees extraordinary potential in one of her older students, Morgan Evans. When Morgan fathers a child out of wedlock, the teacher fears her pupil's chance at an Oxford education may be destroyed.