Vaughn takes Empire on an impromptu trip to the film's temporary editing suite, just another trailer in a sea of trailers stationed near the set, and shows us a couple of very early scenes. The first introduces Shaw and his Hellfire Club – January Jones' Emma Frost, Jason Fleming (Vaughn's lucky charm) as a devilish Azazel and Spanish actor Alex Gonzales as Riptide – revealing their evil agenda to a US military man. Even with exceedingly primitive placeholder effects it's impressive stuff, but it's the second scene that catches our eye. Not only does it suggest that X-Men: First Class will look and feel more like a Eurothriller, it features Erik, on a mission of vengeance against Shaw, confronting a Swiss banker who may be the key to finding his nemesis. It's an intense scene, commendably played entirely in German, in which Erik exudes an air of quiet menace as he tortures the banker (metal fillings are never a good idea) in a callous way that's pure Connery. A sizzle reel of shots also features a moment where Erik use his command of magnetism to yank a gun out of a goon’s hand, before he spins to camera and fires, a moment so Bondian you expect blood to start streaming down the screen.

And Michael is bringing it – Erik is a maelstrom of conflicting emotions, mainly fury and pure hate. Ian McKellen's Magneto may have been regal and malevolent, but you wouldn't have put your money on him in a scrap with Sir Jimmy Savile, let alone a horde of Nazi bastards. This Magneto thought, has teeth. "He's someone who's totally driven", says Michael, rocking a black turtleneck that would make 007 sack his tailor." "If Charles, or any other mutant, gets in his way, he's going to put them down."

With that level of intensity, it's hard not envisage Magneto dominating the movie and perhaps overshadowing Xavier, the de facto hero. After all, at first glance his is the most compelling arc. Vaughn disagrees – that connection with Cerebro gives Xavier his are – but he's not blind to the dangers of having someone truly magnetic as Magneto.

"You come out of the movie going. "Magneto is fucking cool!" admits Vaughn. "And in the other movies, Charles was a bit of a boring, pious, wheelchair-bound guy. But James was desperate to make sure that Charles wasn't boring. And between him and Erik, my God, you want to see these guys going at it. "And you'll get that, too, with Charles and Erick (not to be confused with Charles and Eddie, creators of sunny soul-pop '90 sensation Would I Lie To You?) duking it out in a third-act first-fight that eschews the conversations of the genre. "Fox were saying, 'Matthew, people want to see superheroes use their powers," says Vaughn. "But not on this fucking film. They don't always say I'm going to blow you up or mindfuck you or bend you in half. Sometimes they just want to punch each other. That, to me, is what's different."

In an ideal world, Vaughn would have edited the movie in London. Instead, though, He's moved with the rest of his loyal Marv Films team to a neat little base camp on the fox lot, complete with outdoor Ping-Pong table. You might expect him to be a nervous wreck at this point – delivery date on the film is fewer than two months away – but he's surprisingly chipper today, excitedly showing Empire a piece of the original Death Star model that FX guru John Dykstra has just given him and greeting us with a volley of hilariously indiscreet observations about a number of films and top Hollywood stars.

He then ushers Empire into an edit suite to show us the first few minutes of the movie. When we enter, editor Eddie Hamilton is working on a scene featuring a surprise, and fun, cameo which qualifies as a massive spoiler, and another scene featuring the great Michael Ironside and an actor playing a Russian naval captain who Vaughn is convinced is "Mark Strong's ugly brother". Hamilton quickly removes the undisclosable cameo from the screen and cues up the first few minutes of the movie.

It starts with a recreation of the bold young-Magneto-at-Auschwitz scene that opened Singer's X-Men back in 2000, progressing to an introduction to Xavier as a child, discovering a young, homeless and shapeshifting Mystique rooting around in his kitchen for food, and then heads back to Auschwitz for a raw, intense segment in which Shaw (played by Bacon with grey hair and a creepy 'tache, a world away from the slick Shaw of the '60s) coerces a young Erik into unleashing his powers. It's uncompromising stuff, augmented with brilliant effects (including the Corbould-rigged gag –a collapsing filing cabinet – that so impressed Singer) and is even slightly disturbing. It immediately sets X-Men: First Class apart from the DayGlo superhero fare coming our way this summer, and is a world away from the Mutant 90210 approach that could have been taken. "I can't imagine Green Lantern or Thor starting like that!" says Vaughn. "That's the fun of it. I can imagine people going. 'What the fuck?' But I didn't want to make the kiddie version of X-Men."

Currently, Vaughn's days are filled with meeting, conference calls, more meeting, conference calls about meetings and meetings about conference calls. It’s punishing schedule that has meant he hasn't been able to keep an eye on every aspect of the film – we meet two days after a pair of terrible posters for the film have hit the net and been torn apart by fansites ("It's not my job to market the film," he says, diplomatically) – but it's been an invaluable experience.

Empire had expected that he would return to independent movies having experienced the studio system, but Vaughn says otherwise. I'm looking forward to doing it again now. It’s been exiting, and I’ve learned so much. I really feel we were asked Everest without oxygen and we’re nearly aat the peak and about to put in our flag. We have to get down the other fucking side of the mountain now!" He smiles, and takes a final sip from ever-present cup of Joe, and considers one last question. "What am I most proud of? That I'm not dead!"