Megalopolis need not detain us for very long. The story behind the story is vastly more interesting than what is on the screen. Genius filmmaker Francis Ford Coppola, who once had a clear vision for how to turn Mario Puzo’s pulpy best-seller into a towering work of cinematic iconography, who had already bankrupted himself once trying to reimaging how Hollywood worked in the 1980s, now liquidates a small fortune in order to make his dream project which has been gestating for decades. Sadly, the money men who refused to finance this one were dead right, as it isn’t so much a story as an incredibly lengthy music video, in which random images are juxtaposed in the hope that something of meaning will emerge, but sadly it never does. Busily acting in at least five different films are Adam Driver (fine), Aubrey Plaza (dazzling), Shia LaBeouf (I mean, you know), Nathalie Emmanuel (vacant), Chloe Fineman (huh?) and Dustin Hoffman – who is not so much wasted as carelessly discarded. Avoid.

Of far more interest is The Substance which gives us Demi Moore (able to play a stunning-looking 50-year-old at the age of 60, which is quite remarkable in itself) as fired TV aerobics star and one-time movie actor Elisabeth Sparkle. Desperate to cling on to youth, beauty and all the opportunities those allow, she experiments with The Substance, and with a suitably flagrant disregard for such trivialities as the conservation of mass, she splits open along her spine to reveal a younger, hotter, more Margaret Qualley-ish her. However, The Substance has rules, chiefly that Elisabeth’s consciousness must switch from body-to-body every seven days – no exceptions. But Qualley has far more fun than Moore, so this isn’t easy to sustain.

It’s vital to understand what writer/director Coralie Fargeat cares about and what she doesn’t to appreciate this film. Qualley reinvents herself as “Sue” and strolls back into her old job, which Dennis Quaid’s revolting producer is only too happy to give her. Consider that she has no references, no agent, no bank account, no social security number, not even a last name. Even given that we swallow the magical powers of The Substance (and Elisabeth’s ease with following the very skimpy instructions), what follows is completely impossible. But who could give two shits about any of that when we have the gleeful fun of watching the older Elisabeth’s body progressively falling to pieces as the younger version saps more and more of her life essence away – to say nothing of that completely preposterous grand guignol ending?

What Fargeat does care about is tactility. Everything in this movie, from clothing to medical equipment to flesh to food – especially food – squishes and oozes and rustles and scrapes. From the opening shots, her camera comes right into pore level on the actors’ faces, and the early scene of Quaid slurping down shrimp does something to prepare the ground for the body horror that’s to come – although nothing can really prepare you for the onslaught of the film’s final act.

Moore and Qualley are tremendous, but amongst all of this bravura splatter-gore, it’s two quieter moments that stick with me. The opening overhead shot is a masterpiece of visual storytelling, and the extended sequence of Moore being unable to leave her apartment for her date with an old school friend is utterly devastating. Although both this and Megalopolis look like films of which you could say similar things – crazy, bonkers, you’ve never seen anything like it, etc. – the difference is that Coppola’s film feels like wild horses rode through the screenplay destroying everything in their path, whereas for all its batshit excesses, Fargeat’s film always knows exactly what it wants to be and exactly what it’s doing.

My only criticism is shouldn’t “Elisa-sue” have been “Eli-sue-beth” instead?