Werewolf of London

Wilfred Glendon journeys to Tibet seeking the Mariphasa lumina lupina, a moon-nourished plant. He is attacked by a feral humanoid and bitten, but manages to secure a living specimen. He returns to London with renewed hope that the plant could counter the curse.

Back in London, Wilfred builds a lamp that simulates moonlight in his laboratory and waits for the Mariphasa to bloom. When the first bloom opens, he tests its properties and sees the transformation he fears reversed by applying the plant's sap. The discovery suggests the plant's potential as an antidote, though danger remains.

At a party in London, Dr. Yogami confronts Wilfred and claims they met in Tibet, where he too sought the Mariphasa. Yogami contends the plant could cure lycanthropy, and hints at two Londoners who are werewolves. Wilfred remains cautious but intrigued by the rival botanist's knowledge.

That night, the first blossom opens under Wilfred's moon lamp, and his hand grows fur in the artificial light. He quickly cuts the blossom and applies its sap to the fur, watching the transformation reverse. The moment confirms the plant's antidotal power, though the danger of the full-moon cycle remains.

Yogami visits again and demands two blossoms, warning that the first of four nights around the full moon will trigger a turning. Wilfred refuses to hand over the flowers and cautions Yogami about the peril of provoking the curse. The interruption sets the stage for a desperate struggle between rival ambitions.

Yogami steals two newly opened blossoms from Wilfred's supply, escalating the danger. Wilfred continues his research and hones in on the peril of the coming full moon. The theft intensifies the danger facing Lisa and Paul.

Wilfred declines to accompany Lisa and Paul to Aunt Ettie's party. Soon after they leave, he loses control, transforms into a werewolf, and stalks the city. Ettie's screams frighten him away from Lisa, and he murders a random woman in the street.

Paul Ames reads about the murder in the newspaper and shares the story with his uncle, Colonel Forsythe, Scotland Yard's chief. Forsythe is skeptical, treating the accounts as sensational rumors rather than a genuine threat. The investigation stalls as he weighs the evidence.

With the last blossom yet to open, Wilfred rents a room for the night and locks himself in, but breaks out after transforming. He sneaks into the London Zoo, frees a wolf, and kills a woman who had come for a tryst with the nightwatchman.

The next day, Yogami, out of blossoms, asks Forsythe to seize the plant from Wilfred. Forsythe learns of a dead chambermaid found in Yogami's hotel room, far from Falden, and Paul discovers Yogami's used blossoms. Forsythe becomes convinced there are two werewolves on the loose.

Wilfred travels to Falden Abbey, his wife's country home, and the caretaker locks him in a room. Lisa and Paul arrive to look around the property, and Wilfred, now a werewolf, sees them from a window. He breaks free and attacks, but Paul drives him off, recognizing him.

Paul informs Forsythe of Wilfred's whereabouts, and the investigation deepens. The discovery of Yogami's blossoms and the dead chambermaid leads Forsythe to suspect there are two werewolves on the loose.

Police search all day for Wilfred, who hides in his lab waiting for the final Mariphasa blossom to bloom. When it does, Yogami enters and uses it, and an enraged Wilfred attacks. He kills Yogami and then chases Lisa around the house, knocking Paul unconscious and Ettie fainting in the process.

Forsythe arrives and shoots Wilfred, who dies and reverts to his human form. He comforts Lisa and explains that he will report the death as an accidental shooting in defense of his wife, hoping to shield her from the truth of the night’s carnage.