Doctor Garondet (Paco Villadares) is startled on evening by a knock on his front door, and goes to ask his housekeeper who was there but she is dismissive and says it was merely some boy asking for help at the Orloff Castle. The villagers do their best to avoid visiting the old building thanks to a superstition about who lives there, but Garodent insists on catching the boy and enquiring what the problem was. He does not get much of an answer before he runs off, so ventures into the tavern to ask if anyone can help him on the journey and after surly reactions one coachman agrees to take him, but on the way there the carriage gets stuck and when the doctor get out to shift it, the coachman rides away, leaving him to his own devices...
You would be tempted to think the filmmakers did not want the doctor to reach the castle, never mind the villagers, judging by the degree of faffing about the audience had to endure before the plot kicked off properly. Par for the course for a Jess Franco movie, he being the man who had made the Orloff series a minor name to conjure with in exploitation circles, itself a rip-off of Georges Franju's unforgettable mad scientist horror Eyes Without a Face, but take a look at the credits and you would see that Franco's name was nowhere to be seen. No, he had not turned invisible like the title villain, he was actually getting ripped off himself, or at least he was in the English language dub, as Orloff was placed in nineteenth century settings.
He was usually a contemporary figure in the Franco efforts, but here was introduced not unlike Count Dracula in Transylvania, with muttering villagers warning the hero against travelling to the castle of Orloff, and when he finally arrives being met with a wall of obfuscation that eventually breaks when the Professor demonstrates his proudest creation: an invisible man! Who appears to be purely used as a waiter, moving objects from one surface to another, so that was well worth the effort, wasn't it? Who needs to be reminded of boring old humanity when you could have your drinks served as if there was nobody there at all? Naturally, or unnaturally, the filmmakers were not going to be content with leaving it at that.
If you had seen Paul Verhoeven's Hollow Man you would have some notion of what the invisible menace was going to get up to here, though not before we had a lengthy flashback where Orloff regaled the doc with how he had come about the scientific trickery to manufacture the unseen manservant. Here we saw an explanation of why his daughter (Brigitte Carva, a one and done actress) was such a fragile specimen - she had been buried alive when mistakenly pronounced dead (so a spot of Edgar Allan Poe here as well as H.G. Wells), or placed in the family crypt at any rate, where two of Orloff's staff, the ugly bloke who tends to his grounds and the woman the ugly bloke lusts after and wishes to make his wife, raided it for her jewellery. They were rumbled pretty quickly, and you think said bloke was made into the invisible man.
But there you would be wrong, and indeed when the big reveal of what the invisible man looked like finally arrived, it was, shall we say, not what we were anticipating - let's just say he's not an actual man, or not a conventional one anyway. But before that director Pierre Chevalier had to fathom a method of parting his three main actresses with their clothes: the audience had shown up for sleaze, so that's what they were going to get, by Jove. Maria the sparklers coveter was seen changing clothes (twice!) then her dress falls open when Orloff whips her (so sadomasochism could be added to the list), the maid was stripped and actually raped by the invisible, er, "man" which involved a ludicrous scene of the actress rolling around on a bed of hay and looking anguished (the effects budget didn't stretch to anything further, apparently), and finally poor old Brigitte has her clothes ripped off during the grand finale, apropos of nothing except trying to keep the viewers awake. Even for an hour and a quarter of movie, there was precious little here of substance, real bargain basement stuff solely for the seasoned aficionado of tat. Music by Camille Sauvage.