Dr. Wilfred Glendon (Henry Hull) is a wealthy English botanist who in 1935 on an expedition to tibet was bitten by a werewolf.

In the movie, he travels to the Tibet to investigate a rare flower named "Mariphasa Lupina". He encounters it, but is also bitten by a mysterious creature, after revelated as a werewolf. He returns to London with the flower, and a man named Dr Yogami visited him claimed that he meet him in the Tibet and reveals that the creature is a werewolf and as Glendon is now bitten he is also cursed to transforms in a werewolf, and the mariphasa is an temporaly cure. Glendon uses the flower that same night as he watches his hand now with wolf fur.

Yogami steals a lot from Mariphasa and Glendon the another night is transformed into a vicious night creature. He run to the city and kill a young woman.