If he’d been born a century later, HG Wells might well have exploited the cinematic resources of a Steven Spielberg in telling his celebrated story of voracious invading aliens. As it is, Spielberg’s own War of the Worlds promises to be another blockbuster delivering the director’s signature spin – outsize special effects and the kinds of thrills and emotional touchstones that worldwide audiences can’t seem to resist.

It’s a world away from ET: The Extraterrestrial and Close Encounters of the Third Kind, since the alien visitors in those films were essentially benign, not to mention relatively warm and cuddly. The aliens of Spielberg’s latest, though, are a different matter.

In a group interview Paramount Studios granted to a few journalists earlier this year, Spielberg and megastar Tom Cruise sat together, answering some questions but giving little away. Before that, our group was lucky enough to be able to watch a “refugee” sequence being filmed. In pursuit of just the right shot, Spielberg had Cruise (driving), Dakota Fanning and Justin Chatwin inch back and forth in a battered van while surrounded by luggage-toting pedestrians fleeing the alien menace, repeatedly retracing the short trail on foot and huddling beneath the pounding rain. Water gushing from the rain machines forced us beneath a canvas shelter that fortunately also housed the coffee bar – apparently a gift to the cast and crew from Tom. Later, a media flurry was set off by Tom’s other gift to the set: a Church of Scientology booth, manned by helpful ministers.

Although there had been shoots in other locations, such as New Jersey, the location for these sequences was a quaint, out-of-the-way California village named Piru. After we’d watched the shoot, Paramount people escorted us to the town’s cosy Heritage Valley Inn, where we met Steven and Tom; both mega-celebrities claimed that this was the first time such an interview had been conducted in the middle of a shoot.

The decision to film War of the Worlds, it turns out, was not a recent inspiration. “I would have done this movie 12 years ago,” Spielberg announces. “At an auction, I bought the last surviving War of the Worlds script that had not been confiscated by the police department – because when they raided the Mercury Theater, they took and destroyed every single radio play.” The only surviving copy, Spielberg says, was with Howard Koch, Orson Welles’s co-writer, who was asleep at home when the program aired, recovering from an intense, three-day session preparing the script for its world-shaking premiere. So, the lone copy of the script survived because Koch slept while masses of 1938 listeners thought that the planet was under Martian attack.

After reading it, Spielberg knew immediately that it would make a great movie. “And then the kind of ‘scavenger’ films, came out,” says Spielberg, “that sort of picked the bones of HG Wells over the years; when Independence Day came out, I said: ‘well, maybe I won’t make it’”.

His interest in the War of the Worlds script was re-aroused while searching for a project to make with Tom Cruise. The pair – good friends, used to communicating easily in a sort of cinematic ‘shorthand’ – were determined to work together again after their smooth and enjoyable collaboration on 2002’s Philip K Dick adaptation Minority Report.

Reflecting on the circumstances of their initial meeting regarding War of the Worlds, Spielberg recalls: “We were determined we were going to do a bunch of films together, so I called Tom one day and said, ‘Tom would you ever consider doing…’”

“I came by,” Cruise interjects. “You were doing Catch Me [Catch Me If You Can, with Tom Hanks and Leonardo DiCaprio] and we were looking at TV spots, and you were saying, ‘here’s three ideas’. And I went, ‘OMIGOD!’ War of the Worlds! Absolutely. That day it was done.”

Though dealing with a big, essentially global, theme – one that had perhaps become overly familiar through countless other movies – the two friends wanted to bring at least one narrower focus to the project: “The point of view is very personal,” says Spielberg. “I think everybody in the world can relate to the point of view, because it’s about a family trying to survive and stay together.”

Interestingly, pre-release media coverage has focused on another angle: the story’s resonance in a post-9/11 world, which, as Spielberg is well aware, adds another kind of appeal to an already gripping plot that has been updated for modern audiences. “I feel more at home in today’s world,” he says. “And in the shadow of 9/11, there is relevance with how we are all so unsettled in our feelings about our collective futures. And that’s why when I reconsidered War of the Worlds after 9/11, it began to make more sense to me.”

Playing a father bent on saving his family, Cruise says his actor’s instincts gravitated to the highly personal nature of the story. “No matter how dark [movies] are, I’m always looking for humour and character.” Especially the humour, he says, “because I can identify with it, I relate to it, or I lose an emotional connection with the film.”

“We’ve created the humour,” Spielberg adds, “ but the humour comes out of the natural insanity of this family simply on an odyssey for survival”.

“But maybe we’re the only ones who think it’s funny!” Cruise blurts out.

During the interview, Cruise sometimes appears unsure just how much to let out regarding the film. Though the film’s hostile aliens are being kept a secret, it’s clear that they’re not intended to be funny. And, according to Spielberg, they won’t resemble the Martians in George Pal’s 1952 film The War of the Worlds. “One of the great things the Pal film did was to create, for its time, a tremendous sense of tension and dread,” he says. “A contemporary dread. It really made me feel this event was actually happening.”

In some of the more credulous corners of ufology, it’s long been suspected that Spielberg has some sort of insider knowledge of the “real story” about ETs visiting Earth; and up until this film, he’s always portrayed aliens as beneficent. He once told a reporter that if ‘they’ were here, they were probably decent sorts. But as he said to us: “I’m just an equal opportunity director. I gave the benevolent aliens a couple of shots and now I’m going to try my hand at the worst kind – the kind that are bent on ending civilisation as we know it.”