Fu Manchu (Christopher Lee) and his daughter Lin Tang (Tsai Chin) are alive and well and up to no good in China.
Fu has abducted brilliant plastic surgeon Dr Lieberson (Wolfgang Kieling) and his beautiful daughter (Suzanne Roquette) for good measure. Lieberson is forced to transform a brainwashed Chinese thug into the spitting image of Fu’s arch-nemesis Nayland Smith (Douglas Wilmer) of Scotland Yard.
Fu’s thugs then kidnap the real Smith while he’s on holiday, and replace him with the altered thug, leaving Smith’s best friend Dr Petrie (Howard Marion-Crawford) perplexed by his sudden stone-cold nature.
The imposter Smith murders his housekeeper and is put on trial, all part of Fu’s plans to discredit his nemesis (he plans to do the same with authorities all over the world).
With the real Smith held prisoner at the palace, an American FBI man (Noel Trevarthen) and a local police inspector (Tony Ferrer) team up to uncover Fu’s lair and clear Smith’s good name.
The great German character actor Horst Frank appears as a smirking and misogynistic criminal who travels to Fu with the promise that he’ll be lead by him in a new worldwide crime syndicate.
The Vengeance of Fu Manchu was shot in both Ireland and Hong Kong.