Moulin Rouge wins no marks for its storyline. A struggling Parisian theatre is bought out by an evil financier who wants to marry the venue’s star, Satine, whose heart belongs elsewhere. The show opens like a pantomime with a bantering style and cheesy jokes. And there are passages of physical comedy that look weird amid the glamour of fin-de-siècle Paris. But the slapstick is crisply acted and well directed. And the comic scenes are balanced by full-throttle dance routines played by strutting hunks and twerking lovelies in black fishnet stockings. Every bodice is wound tight enough to ping open at any second. It’s borderline soft-porn but it’s delivered with thrilling doses of self-confidence and brio. Why can’t Olympic gymnasts do stuff like this instead of somersaulting over boxes?

With a company of 50 or more (including a ‘deputy head of wigs’), this is one of the West End’s most lavish productions. The scarlet set designs glow with the alarming radiance of a nuclear reactor during a meltdown. And there’s an eye-scrambling array of coloured costumes on display, like a theme park devoted to giant butterflies. Visual riches explode on every side. The songs, taken from the modern canon of pop, are given fresh twists, fresh energies. Composer Justin Levene has spruced up Adele’s ‘Rolling in the Deep’ and turned it into a pumping hard-rock anthem. And it’s far better than the original (even though that sounds like heresy), because Adele’s voice is too sweet and chocolatey for the material, and her enunciation doesn’t do justice to her brutal, vengeful lyrics.

The show’s first act is all about infatuation. The second act turns to commitment and we follow the doomed affair between Christian, a penniless American composer, and Satine who is mortally stricken with tuberculosis. She keeps coughing into a hanky stained with blood. On paper, their romance is corny. On stage it’s fascinating because the script takes love seriously. And that’s what human beings do. The result is magic. The lead is played by Jamie Bogyo, fresh out of Rada, and blessed with dreamboat looks and a voice that can make your hairs stand on end. Much more will be seen of him. Not much more could be seen of Satine (played by Liisi LaFontaine) because she’s half-naked most of the time. She’s as gorgeous as a Miss World finalist and she sports a bust that would make Raquel Welch weep. Her sensational voice can belt out a showstopping rock ballad as easily as an intimate love song. And she’s excellent in the comic sections too. The supreme talent of these lead actors matches the lavish investment in the show, penny for penny. Rolls-Royce stars for a world-class production. It’s not cheap but it’s unforgettable.

It’s rare to watch a play that makes you wish time would speed up and that your life would end sooner but that’s the distinction achieved by Conundrum at the Young Vic. This 75-minute monologue, produced by the cheerily titled Crying in the Wilderness, introduces us to Fidel, a bore with a high IQ, who rages about his failure to qualify as a doctor. White racism, he hints, caused his disappointment. Fidel appears to be an inmate at an asylum and yet his cell is equipped with a paper shredder, a laptop and a smartphone on which he chats to his dad about lunch appointments. Then again, these devices may be figments of his deranged mind.

A lack of basic clarity makes the show impossible to follow. Fidel varies his bursts of ranting poppycock with arty ballet routines. Now he’s swimming through a maze. Now he’s being struck by a thunderbolt in his ear. Now he’s capturing a butterfly from outer space. Now he’s releasing the butterfly and stretching out his hands to beg a biscuit from his mum. He has no relationships, no choices to make, and no dramatic goal. In other words, there’s no reason for him to be in his own story.

This level of sloppiness might be forgivable in an early draft of a sixth-form play, but visitors to the Young Vic expect professional work. This doesn’t meet that standard. The producers can’t even get the sound right. The venue is a bare studio about the size of a squash court and its acoustics are perfectly all right. But the actor, who studied vocal projection at drama school, wears a microphone attached to amplifiers cranked up to Glastonbury volume. When he raises his voice, he out-screams passing ambulances. Ear plugs are required. The Young Vic flaunts its BLM credentials but it seems to have forgotten what plays are. This is a screed of ill-assorted rhetoric, nicely designed, but with no dramatic mission, no suspense and no ending. Calling it drama is misrepresentation.