Werewolf of London Trailer (1935)

The trailer for the 1935 film Werewolf of London.

Wilfred Glendon is a wealthy and world-renowned English botanist who journeys to Tibet in 1935 in search of the elusive mariphasa plant. While there, he is attacked and bitten by a creature later revealed to be a werewolf, although he succeeds in acquiring a specimen of the mariphasa. Once back home in London he is approached by a fellow botanist, Dr. Yogami, who claims to have met him in Tibet while also seeking the mariphasa. Yogami warns Glendon that the bite of a werewolf would cause him to become a werewolf as well, adding that the mariphasa is a temporary antidote for the disease.

Glendon does not believe the mysterious Yogami. That is, not until he begins to experience the first pangs of lycanthropy, first when his hand grows fur beneath the rays of his moon lamp (which he is using in an effort to entice the mariphasa to bloom), and later that night during the first full moon. The first time, Glendon is able to use a blossom from the mariphasa to stop his transformation. His wife Lisa is away at her aunt Ettie's party with her friend, former childhood sweetheart Paul Ames (Lester Matthews seventeen years older than his "childhood sweetheart"), allowing the swiftly-transforming Glendon to make his way unhindered to his at-home laboratory, in the hopes of acquiring the mariphasa's flowers in the hopes of quelling his lycanthropy a second time. Unfortunately Dr. Yogami, who is also a werewolf (specifically the one who had bitten Glendon in Tibet) sneaks into the lab ahead of his rival and steals the only two blossoms. As the third has not bloomed, Glendon is out of luck.

Driven by an instinctive desire to hunt and kill, he dons his hat and coat and ventures out into the dark city, killing an innocent girl. Burdened by remorse, Glendon begins neglecting Lisa (more so than usual), and makes numerous futile attempts to lock himself up far and away from home, including renting a room far from home at the inn, or with Mrs. Whack and Mrs. Moncaster. However, whenever he transforms into the werewolf he would escape and kill again. After a time, the third blossum of the mariphasa finally blooms, but much to Glendon's horror, that too is stolen by Yogami. After turning into the werewolf yet again and slaying Yogami, Glendon goes the house in search of Lisa, for the werewolf instinctively seeks to destroy that which it loves the most.

After attacking Paul Ames, but not killing him, Glendon corners Lisa on the staircase and is about to move in for the kill, when Paul's uncle, Col. Sir Thomas Forsythe of Scotland Yard, arrives with several police officers in tow. He shoots Glendon once, killing the werewolf of London. As he lies dying, Glendon apologizes to his wife and thanks Col. Forsythe for the merciful bullet. He then perishes, reverting to his human form in death.