Who's afraid of Sigourney?

"I think that with all parents, you don't fear so much for your own safety as the safety of your children. That is one of the reasons I found the script so compelling: how far should one go? How far do you protect innocence? Do you become corrupt yourself, in the process?

"It is a very interesting question and one we did not really answer in the film, apart from the fact you cannot really protect those you love. What protects them in the end is the love they feel for others." Weaver has a reputation for being mentally tough, with a highbrow educational background that includes Stanford University and the celebrated drama department at Yale.

She also has an English mother, of whom she says: "She taught me the importance of having a go at anything. I have always had to try my best."

She is forthright and blunt on both her own career and her industry. "I have been in some terrible movies," she says. "Some deliver what you'd hoped - and some do not deliver at all. And no one really tells the truth in Hollywood. They will flatter and deceive - draw you in and yet stand back when there is trouble. You can't ever be sure of a career or a future. But I either accept that, or get out."

Then there is the question of age. "Once you turn 40 the writing really is on the wall. As for playing someone of 50 whom an attractive man might want to go to bed with ... well, they have a hell of a job getting their minds around that one.

"In Britain and Europe, that is not the case. But in Hollywood, the town of trophy wives, girlfriends half your age - at least - and facelifts? Nope. I am afraid not. So Sophia Loren became my inspiration, as a woman who never apologised for herself."

In 39 films, Weaver has slain aliens, beaten ghosts and tamed gorillas. She has played serious, delivered comedy, chased murderers and been crowned queen of Spain. Her credits include two Ghostbusters films, in 1984 and 1989, Working Girl (1988), the comedy Dave (1993), Copycat (1995), The Ice Storm (1997) and Galaxy Quest (1999).

But it is for the character of Ellen Ripley in four Alien films - in which she does battle with grotesque creatures in deep space - that she is best remembered.

Weaver takes a proprietory attitude to Paul WS Anderson's forthcoming Alien vs Predator, which pits "her" Alien against another horror creation. "I thought, 'I am damned if I am going to be in that.'

"The great thing about Ellen Ripley is that she was given depth and complexity by directors such as Ridley Scott [Alien in 1979 and Alien 3 in 1992] and James Cameron [Aliens, 1986]. She did interesting things and I found her easy to play. She was no cardboard cut-out. I would do another [Alien movie] if I had a director like Ridley and we had a good idea."

IN fact, she has already discussed an outline with Scott: "I said that I did not really want my character to go back to Earth, but would be interested in going back to where the aliens originally came from. We've had a couple of conversations and Ridley is enthusiastic.

"If it happened, I would be very happy. I am just not going to sit at home and write up a treatment, though if I was really smart and wanted to make an absolute fortune, then I would start it tomorrow."

As it is, Weaver earns huge fees - £8.8 million for her last return as Ripley, in 1997's Alien Resurrection, far out-earning her husband's modest salary from the tiny New York theatre that he runs. "Jim is a very secure man," she says. "He has to be. I don't suppose I am the easiest of people to live with. As for money, we both accept that movies pay so much more than theatre. There is no jealousy or dispute. I admire his skills as a director rather than the size of his bank account."

To that end, between filming, Weaver has constantly worked on comedies from unknown writers in Simpson's bijou theatre, The Flea, which seats just 75 in the main auditorium and 35 in the studio.

"I get paid $200 a week, which is why I do movies every now and again," she says. "Jim just directed me in a comedy called Mrs Farnsworth, which was as much fun as anything I've done on screen.

"I am looking forward to another comedy at The Flea more than anything that Hollywood currently has to offer," she adds. "That place is our salvation."