The X-Men finally get their backstory in this terrific prequel/reboot directed by Matthew Vaughn, who reworked the superhero genre in last year's exhilarating Kick-Ass. And it's just what the series needed: a smart, fun, and thrilling movie that spends plenty of time getting to know the humans inside the mutants. James McAvoy and Michael Fassbender play Charles Xavier and Erik Lehnsherr during their formative years, before they become Professor X and Magneto. They battle arrogance, anger, their still-untested superpowers, and eventually each other. As the X-Men are assembled, BFs Charles and Erik are slowly pulled their separate ways toward good and evil. But first they're sucked into a plot by the CIA to stop a nuclear holocaust spearheaded by former Nazi and power-mad mutant Kevin Bacon. It all leads to First Class' most kick-ass scenes, but the movie's soul is in its origin story – the start of something great.