The Wolves of Willoughby Chase

Sylvia leaves her impoverished Aunt Jane to keep Bonnie company while their parents are away. On the train to Willoughby Chase she meets the enigmatic Mr. Grimshaw, who seems to know more than he reveals. The encounter hints at the trouble that will soon envelop the girls.

Letitia Slighcarp arrives at Willoughby Chase as the girls' new governess. She presents a calm exterior, but the girls sense there is something ominous behind her polite persona.

The next morning Bonnie travels by carriage to fetch Sylvia. When the train arrives, Grimshaw is knocked unconscious after a wolf attack, and the girls bring him back to Willoughby Chase. The suspicious incident foreshadows Grimshaw's potential dark role.

The following day Bonnie and Sylvia go out on a sleigh and are menaced by wolves. Simon, a boy who lives in a nearby cave, rescues them from danger and brings a glimmer of hope.

Slighcarp refuses to explain the sudden dismissal of the staff and effectively reduces the household to only James and Pattern. The sisters grow uneasy as the familiar routines vanish.

Bonnie catches Slighcarp in Lady Willoughby's dress and confronts her, but Slighcarp locks Bonnie in a cupboard. Sylvia overhears Slighcarp revealing a forged copy of the will and a plan to sink the Thessaly to claim the fortune, with Grimshaw's help.

Grimshaw throws the real will into the fireplace, attempting to destroy the evidence. Bonnie and Sylvia rescue part of the document, and Sylvia locks Slighcarp back in the cupboard to avoid discovery.

Bonnie pretends to have gone manic to lure the local physician, Dr. Morne, to rescue them. The ruse fails when Slighcarp burns a letter addressed to Morne, cutting off communication.

Slighcarp moves the girls to Blastburn, an industrial town where they must work in a brutal laundry run by Gertrude Brisket and her son Rupert. The harsh conditions take a toll, and a young boy named Joey dies after trying to help.

Bonnie publicly challenges Brisket about the brutal conditions, earning a severe punishment. The two girls are locked in a coal-cellar as retaliation for speaking out.

Simon sneaks in to help with an escape. During the attempt Rupert chases the girls and falls into a giant mangle, dying in the factory. The trio escapes in Slighcarp's carriage and returns to Willoughby Chase.

Brisket and Slighcarp follow the girls in a motorized sleigh; Brisket is pushed off and eaten by wolves, and the sleigh explodes when it overheats, leaving Slighcarp to be presumed dead.

James and Pattern uncover Grimshaw's attempts to flee and capture him, while the Willoughbys survive the ordeals and remain at Willoughby. The household is restored to some degree of order.

Bonnie and Sylvia return home; their parents arrive after surviving the ship's sinking and being stranded on a tropical island. Grimshaw is arrested for attempting to steal the estate's silver, and Lord Willoughby gives Aunt Jane the East Wing so Sylvia can stay with her cousin.