The infamous Spanish Director Jess Franco takes the reins for this fourth outing in the Fu Manchu series, which sees our titular villain (as played once more by Christoper Lee) and his daughter Lin Tang (Tsai Chin) taking up residence in Jungles of South America.
Hiding out inside an ancient Inca temple, for his latest fiendish plot he intends to kill a number of his enemies by using a bunch of female assassins, who have been poisoned with cobra venom, meaning they can kill a person just by kissing them. I'm not quite sure how that works, but anyway. One of his targets, is of course, his arch nemesis Nayland Smith (now played by Richard Greene) in London.
Needless to say, Smith is somewhat perplexed when a young lady calls at his door late one evening and kisses him on the lips. Even more so, when he promptly goes blind afterwards.
Realising what has happened, combined with reports of Fu Manchu operating somewhere in the Jungles of Rio, Smith and his assistant Dr Petrie (Howard Marion Crawford) realise the only way of finding an antidote is to locate Fu Manchu.
And so, despite his affliction, Smith and Petrie head off into the South American Jungle, with the aid of archaeological explorer Carl Jansen (Götz George), hoping to find Fu Manchu's hideout and obtain a cure, before the poison takes full effect.
Notably sleazier than the previous entries in the series, featuring many of Franco's trademarks of female nudity and torture (most of which fell foul of the UK censors at the time). As well as his other trademarks of shaky camerawork awkward zooms etc. This entry in the series plays more like a kind of poor man's "Indiana Jones", rather than "Sherlock Holmes".
Not the best in the series, but it's certainly a decent enough follow up to the earlier films.