“Take it from me, Marianne hips McDonald. I’ve made a living out of being watched.”

After doing her bit for morale in the armed forces, Marianne “Hips” McDonald (Susan George) finds herself alone again (naturally), waking to the sound of flamenco guitars as a couple of shady dudes rock up outside her flat in a sinister-looking black Mercedes.

Clearly not wanting to hang around and see what her visitors want, she puts those hips to good use and says goodbye to Al’s Disco Club Bar, making her way across the dusty Portuguese countryside on foot, accompanied by her own sad theme tune.

Before you can say “Green Cross Code” (or whatever the equivalent was back in 1971… SPLINK?) she’s resolutely refused to look both ways before crossing, and jumped into the road, narrowly avoiding a screaming death by sports car. Her reaction? A shrill and angry “I’m sorry! It was a bloody accident!” before doing a complete 180 and accepting a lift from the driver, Sebastian (Christopher Sandford).

Cue titles. And what titles they are.

Next thing we’re back in England and their meet cute in the foothills has blossomed (as far as Sebastian is concerned anyway) into something special, as he asks for Marianne’s hand in marriage. It’s worth mentioning that without wanting to sound rude, the guy is punching well above his weight here – and the early 70s fashions he’s sporting aren’t exactly helping. The combination of painfully thin frame, “interesting” features, massive hair, big collars, tight trousers and tiny hats (really tiny) is not great, and with the best will in the world, I doubt it was seen as being that great even back in 1971. As if to emphasise this, enter Sebastian’s friend, Eli Frome (alto saxophone). As played by tragic early 70s heartthrob Barry Evans, Eli gets right everything Sebastian is getting wrong. The fashions of the time look timeless on him, and his easy charm is a mile away from Sebastian’s snarky desperation. So it's no surprise that “somehow”, Marianne ends up married to the wrong bloke thanks to a mix-up at the register office.

When Sebastian complains at this outcome, Marianne reacts coldly (“You bore me”) and leaves. It appears (through flashbacks to their time in Portugal) that she might know a little more about shady Sebastian’s motives than we’ve been so far led to understand.

Marianne then bumps back into Eli (Frome, alto saxophone), and then continues to bump into him (if you get my drift) as they decide to consummate their accidental marriage and move in together.

Sebastian meanwhile has travelled back to the continent, on possibly the most polluting plane seen on film, the intercutting between England and Portugal rendered utterly charming by the jarring way the background music changes between locations. Let’s face it, folks – it’s this kind of slapdash approach to film making we all come here for.

Sebastian has gone to see Marianne’s father, The Judge (Leo Genn), who, during a peculiarly stilted dining scene, asks what every father needs to know: “Do tell me, did you fornicate with Marianne?”

But that’s just the start of the weirdness. Marianne’s half-sister Hildegard (Judy Huxtable) is also there, and we immediately learn that a) she hates Marianne, and b) she has got some serious daddy issues.

Sebastian then lets slip that Marianne has married his friend, prompting a vicious beating.

Back in London, Eli (Frome, alto saxophone) too is in trouble, picked up by a pair of heavies, taken to a room with a sign outside that says “Randy? Please ring”, and left in no doubt that they mean him harm in what is, in fairness, an effectively tense scene – mostly due to Evans’ trustingly innocent face. He escapes, stabbing one of the heavies in the process.

Marianne then leaves Eli, too (ostensibly to keep him, and his alto sax, safe). Sebastian, still working for The Judge despite his beating, returns to England, renews his friendship with Eli (Frome, alto saxophone) and the pair do a split screen search for the errant Marianne, who is seen touring the fleshpots of Brighton, looking for work.

Marianne then returns to Eli but finds Sebastian in the marital bed, and the three of them decide to go and sort things out with The Judge. It turns out that The Judge and Marianne’s mother were criminals and somehow, Marianne is due to inherit £1million of their ill-gotten gains on her next birthday. If she doesn’t die (screaming) first. Or at least offer up the details of the Swiss bank account containing the loot.

It’s taken a lot of shenanigans to get here, but now things kick up a gear. There’s murder, more murder, accidental falling down a hole to lonely and lengthy death, torture by sauna, car sabotage and more murder. All spiced up with liberal misunderstandings, unravelling plans, wobbly running around, and dastardly double-crosses. Not to mention quality lines like “Piss off judge, it’s time for the summer recess!” and “They abolished the death penalty mate, or didn’t anybody tell you?” as the film barrels along to a thoroughly entertaining, if grim, ending.

But does anyone die, screaming? Well Marianne doesn’t – and to be honest, doesn’t really come anywhere near doing so. So the film’s lurid title, really the sole reason why it’s even considered to be a horror film, isn’t even accurate.

Which begs the question… why have we all wasted our time writing (me) and reading (you) this review? Honestly. Have we nothing better to do?