Warning: This review discusses aspects of the plot.

In the third of the First Class trilogy begun with such verve and intelligence by Matthew Vaughn and writer Jane Goldman, the 1983 iterations of familiar characters like Cyclops and Jean Grey, discuss another trilogy closer, Return of the Jedi. They debate the virtues of the three movies and conclude, wryly, that no.3’s always the weakest. Well it was true of the original X-Men series and it’s true of this one.

Once Bryan Singer could claim an interloper (Brett Ratner) had burnt the edge and the intellect off his work and left spectacle. Now he’s the interloper, and fans of the series are left to lament what might have been, had Vaughn and Goldman been retained to take the likes of James McAvoy and Michael Fassbender through the ‘70s and ‘80s instead of Singer and writer Simon Kinberg.

One feels the difference in the treatment of the series’ strongest character, Magneto. If First Class gave him a potent revenge arc that tied his fate to that of Kevin Bacon’s Nazi, endowing him with psychological depth and propelling the movie toward a conclusion that was both cathartic and tragic; a climax that tied the end to the beginning with great skill; Apocalypse does a half-hearted and underpowered job of pushing the character forward. We pick him up in communist Poland, an odd choice for an Auschwitz survivor, working in a steel factory and trying to live a low-key existence with his wife and young daughter. When he uses his powers to avert an industrial accident, ungrateful colleagues dob him into the state police, and his family, in a scene mirroring the one that opened both trilogies, pays the price.

This is the tantalising part of Apocalypse, a brief moment when Singer and Kinberg are interested in character building. Magneto’s a damaged victim driven by rage and a sense of persecution, who’s denied a happy life by fearful and oppressive humans. In a Vaughn and Goldman sequel, this would surely have formed the basis for the character’s further development in the next two acts. In Singer’s film, it’s a pretext for Magneto to join the eponymous Super-Mutant, a cross between Imhotep and Hitler, as a willing lieutenant and global architecture critic. His role for the remainder is to stand to one side and move a lot of metal while the big bad grandstands in simplistic, and you have to say, true ‘80s fashion. Hell, he even learns English from TV. How vintage is that?

In a climax that faintly echoes that of the aforementioned Return of the Jedi, Magneto sees sense, realises he’s shackled himself to a despot, and inadvertently saves his son, Quicksilver. But as Singer and Kinberg haven’t had the good sense to reveal the family connection to Magneto, there’s just half as much redemption and no emotional payoff for those moved by the first act destruction of the wife and daughter. The movie’s too busy with orgiastic scenes of pixelated destruction and balletic hand-to-hand combat to pick up character beats like these and turn them into big scenes. Perhaps that’s why the final act of Singer’s movie feels almost monotonous compared with the thrilling end to Vaughn’s.

And that, for the most part, is the story of the entire movie – sketchy character setups, built to a point, then abandoned for a long and exhausting conclusion. There’s not quite momentum in the first half to carry you through the second. Xavier at his “peak”, that Kinberg’s word not mine, amounts to lusting after Rosie Byrne, being controlled by Oscar Issac and encouraging a stronger mutant to save the day. If this trilogy demanded some kind of satisfying, if reluctant confrontation between McAvoy and Fassbender, then we have to settle for a battle by proxy. That’s the problem with choosing a villain more powerful but less interesting than either of the principle characters; he dominates in boorish, scene chewing fashion, replacing a battle of wills between people we care about with an attempt to defeat someone we don’t.

What began as a series with great promise, with a movie easily superior to those that preceded it, ends with an empty second sequel that can boast a few great moments, with Quicksliver once again stealing the show, but little in the way of grounded conflict between mutants and a probing of their psyche that sticks in the mind.

Jean Grey, the future Dark Phoenix, is the case in point. She’s a one dimensional teen with a pained face whose interest to us is attributed in dialogue rather than cultivated on-screen. What she represents is Singer’s flattening effect on this First Class series. He was gifted a terrific cast and layers of psychological intrigue that bested anything in his original series. From there he’s contrived, first in the cross-pollinating muddle that was Days of Future Past, then here, to make them junior versions of those originals – fun but shallow, setpiece props instead of fascinating people. He’s degenerated Vaughn’s original. Not the kind of mutation anyone expected or hoped for.