Dr Henry Jekyll (Paul Massie) is a dull, bookish scientist who spends more time with his lab animals testing theories of alternate personalities than with his beautiful, young flame-haired wife, Kitty (Dawn Addams).
Kitty, meanwhile, has given up trying to find any passion in her loveless marriage to her distant, preoccupied husband and is involved in an affair with one of Jekyll’s old friends, Paul Allen (Christopher Lee), a morally bankrupt wastrel who relies on Jekyll to pay his numerous gambling debts.
After experimenting on himself – despite warnings from his colleague Dr Ernst Litauer (David Kossoff) – Jekyll transforms himself into the young, debonair, and self-confidant Edward Hyde.
In his new character, he befriends Allen, who has no idea that this clean-cut, handsome playboy prone to outbursts of violence is really Jekyll.
As Hyde, he encourages Allen to introduce him to the dark underbelly of London’s opium dens, gin palaces and sex clubs, where he begins an affair with Maria (Norma Marla), an exotic dancer and snake charmer at The Sphinx, a wicked West End club.
When he tries to seduce Allen’s mistress, in reality, his own wife, he is frustrated to find she prefers her decadent lover to him.
In a paroxysm of rage, Hyde invites Paul and Kitty to Maria’s bedroom, where her snake kills Paul, and Kitty throws herself off the balcony through the glass roof of The Sphinx. After strangling Maria, Hyde murders a groom, places the body in his laboratory and sets fire to the place. He tells the police that Jekyll has committed suicide – but then reverts to Jekyll, and the game is up.
Oliver Reed appears in a small uncredited appearance as a nightclub bouncer.
Shot in Megascope and Technicolor, this Hammer film looks gorgeous. It was released in the US as House of Fright.
Dr Henry Jekyll/Mr Edward Hyde
Dr Ernst Litauer
Francis De Wolff