To paraphrase Mrs Merton: what first attracted director Chloé Zhao to the idea of directing something in the colossally lucrative Marvel franchise? Or, to paraphrase Nigel Planer’s fictional actor Nicholas Craig: were they offering Zhao a staggering amount of scope to develop the project?

At all events, it was an interesting idea to hire the brilliant Oscar-winning film-maker Zhao, known for social-realist docudramas such as Nomadland and The Rider. But the very few authorial touches that she manages to bring to Eternals only go to show how dominant the formula actually is. Perhaps there is the question of tone; we had the uncomfortable feeling that the all-important brash humour, DayGlo energy and operatic craziness of superheroism were being downplayed in favour of something more serious – the addictive inspiration of fast food being replaced by vegan cordon bleu. There are some nice touches and an attractive new diversity worn lightly, but this is an underpowered and uncertain film.

The Eternals of the title are an order of divinities with various silly powers and familiar-sounding god-names who have lived incognito among humans for millennia; they include Thena (Angelina Jolie), Sersi (Gemma Chan), Ikaris (Richard Madden), Kingo (Kumail Nanjiani), Sprite (Lia McHugh), Phastos (Brian Tyree Henry), Makkari (Lauren Ridloff), Druig (Barry Keoghan), Gilgamesh (Don Lee) and Ajak (Salma Hayek). They are commanded to protect Earthlings from periodic incursions by alien beings called “Deviants” but must otherwise refrain from getting involved in any of humanity’s wars, although Phastos bitterly regrets introducing us to his super-engineering skills, which apparently led to the atomic bomb. There’s a misjudged scene, treated as a mere passing episode, in which an anguish-filled Phastos stands solemnly in the wreckage of Hiroshima.

A new Deviant attack in London brings the Eternals together for a fightback, but then it becomes horribly clear that the Eternals have been misled and now they must choose between their loyalty to celestial orders laid down from on high, and planet Earth’s humankind, which they have grown to love. This leads to some very protracted set-piece spectaculars, and admittedly amusing scenes for Nanjiani’s character Kingo, who in civilian mode is a Bollywood superstar but is prickly and defensive when it comes to his stalled career as a director. But his status as the comic turn only underscores the heavy and unsatisfying seriousness of everything else.