In her life onscreen, Sigourney Weaver has faced down ghosts, aliens and serial killers, romanced the likes of Harrison Ford and Mel Gibson and studied the clannish movements of gorillas in the mist and of suburban swingers in Connecticut. But before you knew her for any of those feats, an outrageous stage performance bestowed a lesson that has spanned the length of her five-decade career.“It was so good for me,” Weaver said, “to play a girl with a hedgehog in her vagina for a few months.”The year was 1976, and the production was “Titanic,” an Off Broadway play by Weaver’s frequent stage collaborator Christopher Durang (not her frequent film collaborator, James Cameron, who would make his own, very different “Titanic” two decades later). Durang’s sex farce asked her to play roles that ran the gamut from a black widow with deep décolletage to a pigtailed girl hiding a hedgehog in her vagina. The New York Times, in an amused review, described Weaver as “a cover girl beauty with a dry wit” and the play’s principal attraction.But what’s all that praise worth when weighed against one withering comment? One night, after an Actors Studio teacher came to see “Titanic,” Weaver asked for his take on her performance.“Well,” he sniffed, “I didn’t really feel that you had a hedgehog in your vagina.”This season Weaver will be seen in four very different roles, including a teenager in “Avatar: The Way of Water” and an abortion-rights activist in “Call Jane.”Chantal Anderson for The New York TimesUndone by the criticism, Weaver spent the next day overthinking things. Every waking minute was devoted to imagining the hedgehog and mapping out the little creature’s wants and desires; by the time she was onstage that night, throwing her leg onto a table to feed the hedgehog some lettuce, she could swear she felt a real animal moving to claim its prize.And how was all that hard work received? “There was not a laugh in the house,” she said. “It was absolute stone-cold horror.”Well, the performance earned one laugh, at least — a rueful, belated one from Weaver herself, as we sat by the beach at the Venice Film Festival in August. “I think the Actors Studio and comedy may not go together,” she told me, chuckling.Acting can sometimes be a battle between intellect and instinct, and by either measure, the 73-year-old Weaver is formidable. Co-stars talk about the way she marks up her scripts, scribbling down the motivations behind every line, action or lifted prop; onscreen, she projects that intelligence in a calm, cool way and can handily outthink any scene partner. But Weaver’s natural instincts have proved important, too, ever since her first starring role as the resourceful Ellen Ripley in the 1979 sci-fi classic “Alien.”“She’s reduced to instinct and survival, and goes from this person who knows the rules to someone who’s just flying by the seat of her pants,” Weaver said. “So I got a very good drenching in that right away.”The Return of ‘Avatar’The director James Cameron takes us back to the world of Pandora for the sequel “Avatar: The Way of Water.”What to Know: The sequel opens on Dec. 16, 13 years after “Avatar” shattered box office records. If you remember little about the original movie, here is a refresher.Holding Their Breath: Cameron and the sequel’s cast discussed what it took to get the new “Avatar” made and to bring it to life in a changed world.Sigourney Weaver: Hollywood has never quite known what to do with the actress, who has four films out this season, including the “Avatar” sequel. She spoke to us about her unusually fluid career.Back to the Theater: To help reacquaint audiences with the 3-D filmmaking that dazzled audiences in 2009, the first movie was rereleased in theaters on Sept. 23.Some things about Weaver are immutable, like her height (she stands nearly six feet tall) and honeyed voice, but she is credible in comedy, drama and action tentpoles and has put together an unusually fluid career that’s on full display this season. In September, you might have caught her in the indie comedy “The Good House,” in which she played Hildy, a witty, oft-soused real estate agent; the next month, New York Film Festival audiences met Weaver’s Norma, a wealthy woman having an affair with Joel Edgerton in the fraught, Paul Schrader-directed drama “Master Gardener.”Weaver can currently be seen as Virginia, an abortion-rights activist in the period drama “Call Jane” (out this weekend) and in December, she reunites with Cameron in “Avatar: The Way of Water,” despite the fact that her character died in the first film. Since the “Avatar” movies are shot mainly via motion capture, Cameron crafted a whole new role for Weaver, and it’s a corker: She plays Kiri, a 14-year-old, blue-skinned alien.It’s a role that reminded Weaver of her own adolescence and the winding path she has carved since. Born Susan Weaver to a television-executive father and actress mother in Manhattan, she picked the name Sigourney out of “The Great Gatsby” as a teenager, an act of willful reinvention in a life that would be full of such choices. “But I have gotten very far away from the intellectual person I was when I started my career,” she told me in Venice. “I’m pure instinct, and I’ve learned to trust those instincts.”Here are edited excerpts from our conversation.Weaver as a 14-year-old Na’vi girl in the “Avatar” sequel. Early on “I was very self-conscious and shy, so it wasn’t until I hit 14 — when I began to find my footing and I picked the name Sigourney — that my life actually began.”20th Century StudiosDoes this feel like an unusually prolific phase of your career?I’ve just been doing one film a year, but they’re all coming up at the same time as if I threw some magic beans out the window and suddenly there were all these great plants. But I’m happy about it because I’ve always secretly had this dream of being an actress in a repertory theater. Once that didn’t happen, I thought, “Doesn’t matter, I can do it myself. I’ll play the maid one day and the queen another, and I’ll keep jumping around, hopscotching from one genre and one kind of role to another.” So it’s a lovely expression of my earliest dream.When you pick a role, is it informed by the last role you played?It’s never about the role for me, ever. It’s about the script, I don’t even care who the director is. I was an English major, I can’t help it: I know about structure — beginning, middle, end — and I know the story has to be about more than the people in it. If it doesn’t pass those tests, I don’t care how good you are, it’s not for me. The next thing is the director and their vision, and to work with someone who’s passionate. Not with someone who says, “Well, let’s get this over with.”You’ve had those experiences?Only a little. And that’s why I decided I would stay in New York, after going out to L.A. in the ’70s and waiting to be seen by casting people. I felt that in New York, we talked much more about the nobility of our profession, how important it was and also how much fun it was. And being around actors at that time in L.A., there was a real feeling that it wasn’t a noble profession, that you were there to get famous or something. I found it all too confusing, so I went back.Tell me about playing Virginia, the abortion-rights activist in “Call Jane.”Virginia seemed to pop right out of me. I could have been Virginia in another life, I just felt her rangy style in my body. But it was very hard to get the movie financed. We tried to shoot it in other states, and no state wanted us, and Connecticut finally gave us a place to shoot.Were those states rejecting the film because it was about abortion?Maybe they didn’t like the script either, but it certainly was the subject matter. They didn’t want to be tarred with that.A prelude of events to come.Such a prelude, and I didn’t see it coming. I just thought, “Well, it was probably a conservative mayor, or whatever.” I didn’t see the big picture.Opposite Elizabeth Banks in “Call Jane.” Weaver said it was hard to find a state to film in, in large part because the subject was abortion. Officials “didn’t want to be tarred with that.”Wilson WebbDo you remember your political awakening as a young woman?Freshman year, I arrived at Sarah Lawrence, and a bunch of girls were burning their bras — I thought, “Oh, that’s interesting.” It was quite an exciting place, and I happened to be at college during a very political time. Almost every spring there would be protests, sit-ins. Every time I talked about politics, my father [Sylvester “Pat” Weaver, the creator of the “Today” and “Tonight” shows] would say, “Are you on drugs?” And I’d say, “No, not yet. Give me time.”Did you grow up in a conservative family?Well, my parents seemed quite conservative. I worked for a Republican congressman on Capitol Hill for a summer, but I never voted for a Republican. I think as an artist, we tell these stories about self-expression, about the people’s welfare and how vulnerable they are, and I don’t know how you could be a Republican and tell the stories that actors tell. I’m sure I’m wrong, I’m sure there are lots of Republicans that could, but you have to be able to play anyone, which forces you to have compassion for people with other positions and reinforces your conviction that people need freedom.What were you like at 14, the age you play in “Avatar: The Way of Water”?It was a period of my life when my parents were traveling a lot, and I felt a little like a lost soul. I was this tall when I was 12, and I was very self-conscious and shy, so it wasn’t until I hit 14 — when I began to find my footing and I picked the name Sigourney — that my life actually began. I remember so well being that age, and to be given an opportunity to revisit that in a safe way is a great gift, isn’t it?The role is motion-capture. Do you recognize yourself in Kiri, or does the character seem like someone else?I’ve only seen a couple of scenes, but all I hope is that it’s truthful. When I would do my warm-up, I was able to drop 60 years and feel the 14-year-old bubbling up, and then I just let her go.Does she fall in love?I don’t know if I can answer that question. I know that she just wants to be with Spider, a human boy, all the time. Even though she’s seven feet tall and he’s a human, they just complement each other. He actually puts blue on himself to pass, but I don’t think she notices much else besides the fun of being with him and being in the forest. They’re just free urchins at the beginning, and they have a kind of golden life there, even though they’re at war and in hiding.“If you’re tall, people expect you to be more mature, and for many, many years, I was not that.”Chantal Anderson for The New York TimesNorma, the character you play in “Master Gardener,” is at the other end of the spectrum. She makes every situation so fraught — even the way she wields a wine glass is like it’s a loaded gun.She’s certainly one of my favorites. Norma is a really complex character — I saw her referred to as icy, but I think she’s a cauldron.She can operate at a remove, but it’s not an icy remove.I’m so glad you see that because I think there’s a tendency to dismiss older women and, if they’re wealthy, to refer to them as icy. It’s one of the best parts I’ve ever had, but I’ve always avoided that kind of character.She’s a fun character to watch, because she’ll so often say or do something that’s wildly inappropriate.It’s one of the best roles I’ve ever had because she is so complex and was never meant to be one thing. There used to be so much emphasis on playing a woman sympathetically, and they only do it to women — nobody worries about the man being sympathetic. Also, I must say, it’s great to play competent women who still have sex lives. It’s something that didn’t used to happen that much in the old days, so I feel very optimistic for me and my peers that as long as they make good stories, older women are going to be a part of it, because they are very powerful in our real lives.When do you feel most powerful in your own life?Gosh, I’m not sure I know how to answer that. Powerful. Well, the Supreme Court decision made me feel very un-powerful, and I think that’s what a lot of women are feeling.In the 1980s, as you were coming into your own as a movie star, did you feel powerful?Whenever I used to go to Hollywood and have to deal with these different studio heads, I was never comfortable. I always felt incredible sexism there, and a kind of resentment that they had to listen to me because I did have this power and I was smart enough to put several sentences together. I used to think, “Oh, it would be fun to direct, but I don’t want to have to deal with those people.”I remember I was trying to raise money for our theater [she was a founder of the Flea Theater in New York], and I asked a studio I have a good connection with if they would make a charitable donation. And they said, “You know what we’ll do? We’re going to give you a bonus, and you can sign that over to your theater.” I said, “It’s not really the same thing. I can make my own charitable contribution.” I was so astonished by their lack of interest, and you’d think after several movies together that there’d be some kind of mutual respect.“I have gotten very far away from the intellectual person I was when I started my career,” Weaver said.Chantal Anderson for The New York TimesIn a 1994 interview, you said, “I always felt a little bit illegitimate. Whenever they talked about serious actresses, I always felt that I had one foot in the land of Arnold Schwarzenegger, one foot in the land of Ivan Reitman and maybe a toe in the land of Meryl Streep and Glenn Close.”If you’re a woman, they want to know, are you a babe? Are you a comedian? Are you this or are you that? They didn’t know what to do with me. It was always off-the-track directors who would wake up in the middle of the night and go, “Oh, Sigourney Weaver, she could do this.” And then these things would come to me out of nowhere.After “Alien,” I was sent all these serious-person scripts and most of what I’d done was comedy onstage. I thought, “God, when am I going to get back to that?” That has been frustrating because a good comedy is hard to find, and so are love stories — I love them, but they couldn’t really imagine me in a love story. If I came in the room, all the producers would sit down, and if there was a leading man, he’d usually sit down, too, because they wanted someone different, someone much smaller.Did you feel pigeonholed because of your height?If you’re tall, people expect you to be more mature, and for many, many years, I was not that. I think because of my career, I’ve kind of fooled people into thinking that I’m a serious person. There are some things I feel quite serious about, but in general, I’m on the silly side. I think that’s why I love working with Jim Cameron — if it’s an adventure, let me at it. But this is something any actor has to deal with. Anytime a movie registers, you get 10 more offers like that — after “Ice Storm” [1997] I got so many mean, cold ladies. I think the only recourse is just find things to surprise yourself, and you’ll surprise your audience.What’s a good example of that?They didn’t want to see me for “Galaxy Quest” [1999], but I thought, “This is my chance to show my own insecurity when I go out to L.A.,” because no matter who you were, [Hollywood] could make you feel as vulnerable as [her character] Tawny feels. It was one of the reasons I made her such a babe: Babes should have all the friends in the world, but I’m not sure they feel secure about that because they think it’s only skin-deep when it’s not.So now that you have planted these magic beans, and by sheer luck they’ve all bloomed at the same time, what do you do with this garden that you have outside your window?I don’t want to pick it! Probably no one will get as much enjoyment out of these four films as I do. Imagining Norma and Hildy and Virginia and Kiri together, I just feel like I hit the jackpot, man.I would love to see those four characters in a room. Who would get along?I’m not sure what Kiri would think being in a room like that — I’m sure she’d find Norma completely terrifying. I guess it would depend on what kind of wine Hildy brought to the gathering. More