The childless widow of Allan Fury bequeaths the Fury estate to her Fuller relatives, but Allan's illegitimate son who masquerades as a servant hopes to grab the estate for himself.
Ambitious poor relation Blanche Fuller accepts a job as governess from her wealthy cousins who have adopted the name Fury since they acquired the ancestral home of the Fury family. Blanche plots to become the lady of the manor but her illicit passion for the vengeful, obsessed Philip Thorn sets off a string of tragic events, including murder.—Anonymous
Blanche Fury, née Fullerton (Valerie Hobson) is in bed, very ill, giving birth. She starts remembering her life.
She has been through several positions of employment before and lost them due to her independent nature. She is given one last chance to be the hired companion for a irritable rich old woman, Mrs Hawkes (Margaret Withers). However, she receives a letter offering her another position and she leaves Mrs Hawkes after having given her opinion of what she thinks of her.
She is the new governess at the mansion of the Furys with a far superior salary. There, she comes to terms with her distant cousins. Her task is to teach and accompany young Lavinia (Suzanne Gibbs). However, the most complicated man within the household is Philip Thorn (Stewart Granger). He's an illegitimate child of the late father of the family, and he's suing the family so that he can inherit everything.
There is a gypsy encampment near the village. Phillip enlists her aid in recovering some horses that were stolen by the gypsies and she is attacked by some of them. She and Phillip fight their way free and escape with the horses successfully. This angers the gypsies into seeking revenge. Blanche falls in love with Philip; however, she prefers to marry the wealthy son of the family, Simon (Michael Gough). Philip is told by his lawyer that they couldn't find any proof of his mother having married secretly in Italy. He is then driven by the heritage that he feels in his blood and the legend of the symbol of the family that guards it. When a beloved old horse is shot and killed because she can no longer profit the owners with foals it is the last straw. Philip murders the father (Walter Fitzgerald) and son in the disguise of the gypsies. This is easily believed as the gypsies had plenty of motive and had tried to take vengeance before by burning the family barn and been caught. Blanche knows that he did it because she saw him at the window that night and she aided in the murder by not warning her husband and his son or calling for help as she was told to do.
Philip undergoes a change in personality because of the murder. He begins to behave as if he were the master of the place, although Blanche tells him to be discreet. He tells her that the only thing which stops him from being master and commander is the little girl, Lavinia, but Blanche won't allow him to kill the innocent child who will inherit everything in time. She changes her testimony and accuses Philip of the murders after he encourages the little girl to attempt a dangerous jump with her pony, in spite of Blanche warning him not to harm the child. Philip is sent to the gaols.
At the trial, Philip insists on defending himself. Blanche gives her evidence, and accuses him of plotting against Lavinia. However, Philip is defending himself well, so it seems as if it were just Blanche's imagination. However, Blanche asks for permission to sit down, as she is heavily pregnant. This makes Philip stop, he realizes suddenly that he is the father of her child, and that the child is going to have the opportunity of being the rightful inheritor of the mansion and all its privileges. So Philip allows himself to be convicted with no further defense.
The day that Philip is executed Blanche tries to stop Lavinia who is determined to try the jump on her pony. The child is killed and Blanche carries her body back to the estate in grief. This provokes Blanche going into labor too soon. She will die, but the child will live and will be the sole heir of the estate. It is suggested that this has been fated from the beginning by the legendary guardian of the place and family and all is back in the hands of the rightful blood heir, Philip's son.