Abel Mason is courting Helen, who is told by a rival for her hand that there is madness in the Mason family. She is persuaded to reject Abel for the sake of her unborn children. Two yeas later, her husband dead, and herself dying, Helen entrusts her baby daughter to Abel who take the child in but for the purpose of wreaking revenge on his former lover.

18 years pass and the young Helen has grown up, a child of nature, fond of animals and children but bullied and mistreated by the man she thinks is her father, Abel. She meets Martin, a student working as a farm hand and they fall in love. Abel tells Martin of the madness in the Mason blood and Martin, like Helen's mother before him, eventually breaks off his engagement for fear of the sickness recurring in their children. Helen is distraught and tries to follow Martin who hides from her on the hills and here she is met by Fielding Day, a tramp and 'evil companion of Abel's Youth' who has entered into an agreement to marry Helen in return for a share in the farm and is to make her as miserable as Abel has been. Helen accepts his proposal only because it will stop people talking about how Martin jilted her.

A year later, in a miserable marriage and looking after Abel, now paralysed by a stroke, Helen is told that he is not her father. She tries to drown herself but is rescued by a local farmer who takes her to his home where she meets Martin who has returned, unable to forget her. He is sick, but rallies when he sees Helen. Seeing them together, Fielding Day beats Helen severely. Helen leaves Four Gates and she and Martin flee into the hills, pursued by her husband who attempts to shoot them. He is prevented by a farm hand who has a grudge against him and falls and breaks his neck, leaving the couple free at last.