X-Men: First Class delivers the X factor

Really, a prequel is a creation myth and, from the big bangs of science to the Edenic yarns of religion, we all love a good creation myth. That's partly why X-Men: First Class is such fanboy fun, as the script departs from official Marvel lore to invent a whole new "origin story" for the mutant ensemble. Does it stretch credulity? You bet, but no more than Adam's rib. What's better, the fabricated stuff is blended with actual history during the height of the Cold War, leaving a sombre JFK to share the screen with fire-breathing dudes and shape-shifting babes. Camelot, indeed.

Creation begins during the dark days of the Second World War with a study in contrast: Two young males, one in a Nazi concentration camp, the other in a sprawling Westchester mansion. Their back stories couldn't be more different but, yes, they do a share a singular trait. Both are irradiated "children of the atom," simultaneously cursed and blessed with a potent genetic mutation. In the camp, Erik witnesses the death of his mother at the barbaric hands of Dr. Schmidt. In the mansion, Charles witnesses a more benign sight – another mutated kid – and exclaims in delight: "I thought I was the only one."

Flash forward to 1962, when Charles, fresh out of Oxford, is en route to becoming Professor X (James McAvoy); when Erik, hot on the trail of his mother's killer, is set to morph into Magneto (Michael Fassbender); and when that new kid on the block, she of the blue epidermis, is slinking her way toward Mystique (Jennifer Lawrence). At this early stage, they're all still in mid-metamorphosis, only partly emerged from the cocoon of normality, adjusting to their peculiar talents and not yet hardened into sworn enemies. As for the evil Dr. Schmidt, he's now the evil Sebastian Shaw (Kevin Bacon) and seems to be deploying his superpower to manipulate the Superpowers – inveigling himself into the minds of U.S. and Soviet generals alike, encouraging the former to stick nuclear missiles in Turkey, the latter to plant them in Cuba. Well, you know what's about to erupt.

But before the near-tragedy comes the comedy. British director Matthew Vaughn, who earlier tickled our funny bone in Kick-Ass, takes consistent pains to put the comic into the book. The dialogue is the bantering sort that's easier to enjoy than to quote – hardly scintillating wit, but definitely light and bright and quick. Also, stealing a page from Bryan Singer, the franchise's original director, and aided by the strong efforts of a uniformly solid cast, Vaughn gets the pop mix just about right, neither overpromoting the action nor underselling the characters. Instead, as with Singer, there's a delicacy to his direction that gives us room to breathe and, even over the usual inflated running time, reason to linger.

Consequently, I won't dwell on the plot but will leave you to enjoy its swirling twists and to spot the embryonic X-sters new and returning – such as Emma Frost the ice-dolly (January Jones dripping cleavage) or Wings the incendiary angel (Zoë Kravitz spewing flames). At various stages, they must choose sides in the vast Marvel wars to come, even while preparing for the climax here – that showdown in the Atlantic as the opposing fleets gather and the Cuban Missile Crisis flirts with meltdown. Enter JFK, seen on black-and-white TV and looking awfully worried. If only he'd known. Turns out that, during those tense 13 days in October, the world was saved not by mere Kennedys huddled in a state room but by an uberbreed taking matters into their own clawed, magnetic, furry or otherwise mutated hands. Historians, prepare for a rewrite.

Once again, given the civil-rights era setting, the mutant metaphor is a moveable feast, representing just about any persecuted minority you care to mention – Jews in Nazi Germany, blacks in the American South, gays in homophobic places and, of course, teenagers everywhere. Repeated too is the central conceit of the mutants divided against themselves, but now we're present for the birth of the warring philosophies. Sequels merely ask "And then what?" but prequels pose the more pressing question of "Why?" and this one does a nice job explaining how the Professor and Magneto evolved into the Martin Luther King and Malcolm X of their race – peaceful integration pitted against vengeance by any means necessary.

Ideally, this pretty good beginning would make for an even better end but, alas, franchises don't work that way. Rather, when the weekend box office shouts its tally, First Class will surely double as a fresh start. So expect the worst – sequels again.

X-Men: First Class