The premise, it turns out, came from none other than Steven Spielberg, and it went like this: “A married couple drop their child off at college; not long after, the wife starts to feel there is a presence in her home. At first, she thinks it’s someone who used to live there, then she starts to believe otherwise.” Gregg thought through the concept while driving cross-country. “And, by Nebraska, I had it,” he says.

In What Lies Beneath, the Spencers (Harrison Ford and Michelle Pfeiffer, above) discover that there is a “presence” in their home. And water is its favourite element. Which is why Pfeiffer (who admits that she has “always been paranoid” about going underwater) had to spend much of her time on the set dripping wet - even if some of the more unpleasant scenes were done with mirrors (below).

In What Lies Beneath, Pfeiffer plays Claire Spencer, a fortysomething housewife who watches her only daughter pack up and go to college. Left alone in her tranquil New England house while her husband, Dr Norman Spencer (Harrison Ford), works on a research project, Claire begins to hear voices, see ghostly images and comes to believe she may have witnessed her neighbour murdering his wife. So is this the beginning of a nervous breakdown? Or is she just suffering from empty-nest syndrome? Or has she begun to unravel a mystery that might just lead to a closer examination of her own marriage?

Any film aficionado might think the premise of What Lies Beneath was in the spirit of classic Hitchcock. But Harrison Ford sees things rather differently. “Frankly,” he admits, “I never was scared by any of the Hitchcock films.” For him, the scary elements of What Lies Beneath come from the reality of the characters and their relationships. “These days, we tend to make up scary stories out of violence, long knives and ladies who take showers,” he says. “But this film is more maturely developed.”

Zemeckis is also wary of parallels. “Hitchcock’s definition of suspense is the audience knowing more than the characters in the movie,” he says. “A mystery, by definition, is the antithesis of that: mystery involves misleading the audience. I’ve broken this film into two parts: it’s a mystery, then it becomes a suspense movie. But all through the mystery, we have these surprise shocks to Michelle’s character.”

In other words, be prepared for fluttering curtains, hints of madness and the fearful ascent of stairs - not to mention gliding camera movements and, of course, a jittery score. But, unlike such movies as Scream, I Know What You Did Last Summer and the Halloween series which relied on gore to achieve their impact, Zemeckis set out to make a decidedly more adult film.