‘Hunt the Flop’, the Royal Court’s bizarre quest for dud plays, has found a candidate for this year’s overall prize. Instructions for Correct Assembly by Thomas Eccleshare is a family satire set in the near future. Plot: suburban parents replace their missing son with a computerised cyborg which malfunctions. That’s it. Were this a pitch for a TV sketch show the producer would say, ‘OK, but then what?’ The answer here is virtually nothing.

Early on, the cyborg makes embarrassing political statements and expresses support for Brexit. The parents hastily silence him using a hand-held device that returns him to their dead-safe Guardianista outlook. This gag is extended later when the cyborg does the ‘drunken uncle’ routine at a party and makes sexist overtures to two women. These patchy comic efforts are the play’s only highlights. The meandering script has an error that any competent producer ought to spot: a lack of conflict between the parents. One should be keener than the other on the experimental cyborg. But without that dynamic the play becomes a fallow heap of biscuit-mix banalities. Confusingly, the production features flashback scenes that involve the son before he disappeared. But the son and the cyborg are played by the same actor, with no change of costume, and it’s unclear that these scenes belong to the past. It took me an hour to realise that the play was using two timescales in parallel, and yet, weirdly enough, this discovery added no depth or interest whatsoever.

Two fine actors are squandered here. Mark Bonnar, adept at playing middle-class nuisances, brings some welcome touches of physical wit to the show. Opposite him is Jane Horrocks, one of the best comediennes in the business. How did they end up in ‘Hunt the Flop’? Their agents should try harderto find them work that exhibits their talents to best advantage. That may mean declining future offers from the Royal Court, which was once the proud champion of new writing and has now become its coffin.

Loaf-mania hits the Dominion. The musical Bat out of Hell is the work of Jim Steinman who composed Meat Loaf’s greatest hits. He appends his favourites to a romantic storyline set in a dystopian city of the future. Strat is the chief of the underground rebels and he falls in love with Raven, a pampered heiress, whose tantrum-prone dad, Falco, wants to kick the squatters out of their subterranean ghetto and convert the tunnels into chic apartments for yuppies who don’t mind living below sea level. The rebels are additionally troubled by a mysterious DNA freeze which halts the process of senescence once they reach the age of 18. (I didn’t quite follow that bit.) Old man Falco and his drunken wife have a troubled relationship, which is hard to decipher. One minute they’re carping and bitching like grouchy pensioners, the next minute they’re stripping half-naked and grinding suggestively across the bonnet of a tail-finned sports car. (I didn’t follow that bit either.) With her parents distracted, Raven admits Strat to her bedroom for acrobatic romps whose excitement is vastly increased by the risk of discovery.

This narrative is daft, of course, and not a little confusing, but the director Jay Scheib knows that the occasional longueur will be tolerated if it leads to a pumped-up full-cast dance routine performed to parade-ground standard. The show delivers several of these electrifying moments. The hits are well positioned, too, which helps. The title number provides the climax to Act One, and the schmaltzy ballads (‘I Would Do Anything For Love’ and ‘You Took The Words Right Out Of My Mouth’) are shrewdly delayed until Act Two. Nevertheless I wondered if the capital had enough metal heads to fill this hangar-sized theatre. Then I noticed something. Next to me a suntanned grandmother was mouthing along to the lyrics. As I glanced down the row I saw two more refurbished matriarchs doing the same. I also spotted some teenage girls bobbing their heads and lip-synching to the words, as if in a trance. (Note for anthropologists: the miming of the words seemed to be a female-only indulgence.)

I guessed that at some point the Loaf-heads would leap out of their seats and mob the stage. And they did. Well, I say they. In fact, a solitary Loaf-er sprinted to the footlights with his arms manically upheld, two fingers on each hand extended to make a bullhorn salute. He stood there waving like a crazed maestro but nobody joined him. Perhaps because he didn’t fit the classic image of the headbanger. He was about 60, greying, balding and bespectacled, wearing a shirt, a jacket and a yarmulke. His frenzied antics at the footlights must have delighted the show’s investors. A musical that appeals to elderly Hebrews and to glassy-eyed teenage girls could last for ever.