Hugh Jackman’s Wolverine goes back in time to 1973 in a bid to prevent the future extinction of the X-Men.
That is the perfect plot device for this superior superhero adventure to cunningly unite the comic-book mutants’ older and younger selves.
Wolverine lands in the era of lava lamps, waterbeds and dodgy hairdos, which is good for a laugh before things turn serious.
His mission: spring Michael Fassbender’s Magneto from an impenetrable prison and stop Jennifer Lawrence’s shape-shifting renegade Mystique from assassinating a scientist (Peter Dinklage).
The jailbreak, which sees mischievous young mutant Quicksilver (Evan Peters) zipping around so swiftly that time appears to be frozen for everyone else, is the film’s most giddily entertaining episode.
Elsewhere, the time-travel plot sometimes get overly knotty, but the acting has an emotional clarity that cuts through the storyline tangles and makes the film’s crises and dilemmas unexpectedly affecting.