Ah, to be young and a mutant. To be able to read minds, to soar high above the clouds, even to shape-shift into a supermodel one lonely night at the bar. Sounds like a blast? Think again.

The genetic anomalies of X-Men: First Class are a conflicted bunch, initially baffled by their superhuman gifts and, ultimately, persecuted because of them. They are feared, reviled and misunderstood, but when the world seems to teeter on the brink of nuclear holocaust, as it did during the Cuban Missile Crisis of 1962, they prove uniquely talented as peacekeepers.

Some of them, anyway. The mutants fall into two camps – those, like Charles Xavier (James McAvoy), who envision harmonious co-existence with ordinary mortals, and others, like the reptilian Sebastian Shaw (Kevin Bacon), who regard man as an enemy yet to be vanquished.

Xavier, better known to X-Men fans as Professor X – and played in the saga’s first three installments by Patrick Stewart – has typically been portrayed as the very embodiment of benevolence, a soothing father figure to mutants seeking to live in the world rather than dominate it. Here, he’s a dashing cad, dropping witty, well-rehearsed pickup lines over a glass of scotch, but in McAvoy’s ever-curious clairvoyant, we witness the rise of a born leader.

It’s inevitable that Xavier and best friend Erik (Michael Fassbender) will part ways, their youthful bond eventually severed by clashing philosophies. Embittered by the horrors of a childhood in Auschwitz but still less jaded than Magneto, the super villain he will become, Erik channels his powers best in anger. That he casts a disdainful eye on humanity is unsurprising, but here, in an origins tale heavy on exposition, he is less monster than misguided soul.

Together, for different reasons, he and Xavier take on Shaw, who plans to accelerate the extinction of mankind by playing Russians against Americans at the height of Missile Crisis paranoia. (Bacon, as the sociopathic puppet-master, is delightfully slimy, and too little seen in the movie’s later passages.)

Despite director Matthew Vaughn’s audacious attempt to cram volumes of backstory into a perfectly sturdy stand-alone adventure, First Class never feels labored or constrained by Marvel mythology. New mutants and human antagonists drop in and out of the story, sometimes without fanfare or explanation, but the movie’s pacing is brisk, assured enough to keep us diverted.

So too are the performances. Thanks in part to a cast of hungry, energetic stars with presence to spare – Fassbender, a formidable talent, radiates the kind of brooding intensity a young Ian McKellen might have mustered – and to a story, co-written by Vaughn, that never stops gathering momentum as it careens toward a conclusion that begs for yet another sequel, it is a rewarding slice of pulp fiction.

Can it save a franchise sputtering in recent years on fumes? Surely. After a perfunctory Last Stand (2006) and the overall sloppiness of Wolverine (2009), it reinvigorates the series with a sense of purpose and direction. It’s exactly what the professor ordered to make the heroes of X-Men seem super again.