For a long, bleak stretch last winter, nothing was going right on the New York City set of Ransom. The worst blizzards in decades had turned the Big Apple into the Big Slushball; the movie's star, Mel Gibson, had suffered an attack of appendicitis--and everyone else had a cold. In the midst of this mess, Rene Russo, playing a woman whose child had been kidnapped, was feeling frustrated as she tried, shot after shot, to convey the deepest levels of maternal pain and fear. "I've never worked harder," Russo says. "Several times a day I had to put myself in this place of raw emotion. I was struggling."

Worst of all, Gibson, despite his physical problems, was making it look easy. As an entrepreneur--and Russo's husband--Gibson had to project the same anguish and dread. But, Russo says, far from being tense about his performance, Gibson "was cracking jokes, getting the whole set laughing, right before the take!"

Seeing her exasperation, Gibson took Russo aside. "I used to do that," he said, referring to the torture she was putting herself through. "But I stopped. You've got to go to the set with nothing, and when the director says, `Action,' just go there." Russo listened to his speech in praise of spontaneity, and, she recalls, "I said, `I don't know what you're talking about.' But then I did the most dramatic scenes in my life, and I was right there with him. It was wonderful."

Gazing into those sapphire eyes, who wouldn't believe this man could calm fears and drive out demons? At 40, Mel Gibson seems to be supremely serene in his own skin--an accomplished actor who commanded a $20 million salary for Ransom (which opens Nov. 8); an Oscar-winning director and producer (for 1995's Braveheart); and by all accounts a devoted husband to his wife of 16 years, Robyn, 40, and the doting father of their six children. The tabloids no longer run pictures of Gibson carousing in bars with other women. Lately, all they can say is that he is smoking again--and that he once ate dog meat while making a film in Taiwan. ("It tasted," Gibson said, "like rabbit.")

Not that Gibson has lost his eye for the ladies. While shooting Forever Young in 1992, Gibson watched actress Isabel Glasser rehearsing an entrance, then leaned over to director Steve Miner and said, "She's got great ankles." Miner agreed--and shot the scene starting at floor level so the audience could experience the same view. "It was a clever observation that made the scene better," Miner says.

Gibson can also be flirtatious in a rough-hewn way. Rosanna Scotto--a TV anchorwoman for Fox News in New York City who has a part in Ransom playing herself--says that when she first met Gibson, he pretended to trip into her, which forced her, in turn, to grab him. She didn't mind. "I told him that Ihad teased my husband about a kissing scene I was going to do," she says. "He said, `Don't worry, darlin', by the end of the day we'll be swapping spit.' " Friends say such behavior is all for laughs. "I tried to get him to pick up girls with me," says Miner. "He wouldn't do it. He's a serious family guy." In fact, Gibson sounds as if he has thought a lot about commitment. "People are chasing things they can't get. They're just illusions," he told the New York Daily News. "Too many people go into marriage too lightly. You've got to take it seriously. Go in there wanting to make it last."

Not so long ago, though, he was a different Mel--brooding, boorish and quick to lose his temper. He could shoot his mouth off--most infamously when he made sneering remarks about gays in a 1991 interview with the Spanish newspaper El Pais. One big problem with the old Mel was alcohol. Gibson drank heavily while making films including The Bounty (1984) and Mad Max: Beyond Thunderdome (1985)--and reportedly put his marriage in jeopardy. But close friends say Gibson has changed. "He's a better actor and takes it more seriously," says Thom Mount, who produced Gibson's 1988 thriller Tequila Sunrise. "He's grown up a lot."

At least he has learned what's good for him and what's not. "I'm a workaholic," he told the Tampa Tribune. "I unwind by working." During the filming of Braveheart, "God knows what time he left the shoots at night," says extra Tam McDermott. "He was always there." As for that appendicitis attack he suffered during Ransom, soon after leaving the hospital he shot a scene that required him to run full-bore up Madison Avenue and roll across the hood of a taxi. "He insisted on doing it," says producer Brian Grazer. "It was so cool."

Dedicated as he is, though, Gibson refuses to take himself or his projects too seriously. During the shooting of Braveheart, an actor performing an emotional scene might look up to see that one of his costars, at Gibson's instigation, had slipped on a red rubber clown nose. When the Sunrise set tensed up over a nude scene he was to perform with Michelle Pfeiffer, Gibson, says producer Mount, "made everybody laugh and get through it [by] jumping out of his trousers. He's wonderful in situations where there's tension."

On the set, Gibson is aggressively egalitarian. When his children were visiting the set of Braveheart, a weary battle-scene extra reportedly asked one to fetch him a cup of tea. The reluctant youngster looked at his father questioningly, says McDermott, "but Mel said, `Go and get it.' He is bringing his children up very straight."

Gibson looks like a softie compared with his own father. Now 78, Hutton Gibson was a brakeman for the New York Central Railroad, raising his fam-ily in Upstate New York, when he injured his back on the job. In 1968, Hutton took his Workman's Comp settlement and moved his wife, Anne--who died at age 69 in 1990--and their five sons and five daughters to Australia, his mother's birthplace, in order to keep his sons out of the Vietnam draft. (Mel, the sixth-born child, was 12 at the time. His parents adopted another son in Australia.) Hutton Gibson was no hippie, though; he was a strict disciplinarian, a staunch Roman Catholic--and a great influence on Mel, who at times has declared his opposition to abortion and birth control, and has even expressed doubts about evolution.

In Australia, Mel (who holds dual citizenship) attended an all-boys Catholic school where he was taunted for his American accent and became, he has said, "a loner" and a "daydreamer." Acting was something "I was in training for before Iknew I wanted to do it," Gibson told PEOPLEin 1985. After graduation he thought of becoming a chef--Gibson has said he can cook anything "from Japanese to Italian"--but, without his knowledge, a sister sent an application on her brother's behalf to Australia's National Institute of Dramatic Art.

He was accepted in 1974 but was lackadaisical about his career. As Gibson likes to paint it, a fat lip led to his big break. Shortly before a movie audition in 1979, he has said, he got into a barroom brawl. "I was a mess," Gibson told The Washington Post. "I had stitches in my head. I was peeing blood. I couldn't see." But the audition was for Mad Max, and Gibson showed up with precisely the burned-out, beat-up look director George Miller had in mind for his postapocalyptic tale. The Road Warrior, the second installment of Miller's eventual trilogy, would, along with the 1981 World War I drama Gallipoli, launch Gibson to international stardom.

But success, Gibson complained at the time, was "all happening too fast." He made The Year of Living Dangerously, The Bounty and The River in quick succession. In 1984, in Toronto filming Mrs. Soffel opposite Diane Keaton, Gibson, driving drunk, ran a red light and collided with another car. He was arrested and fined $300, but the judgment he really had to sweat was that of his wife. "I get my ears boxed if I'm not home by midnight," Gibson once said. Robyn Moore, the future Mrs. Gibson, met Mel in 1977 in Adelaide, Australia, when the struggling actor moved into a house shared by Moore and others. "It wasn't a huge romance straightaway," Gibson has said. "We became great friends first." In 1980 they became husband and wife.

Robyn was upset with Gibson after his Toronto arrest, but he was still drinking in 1985 while shooting Mad Max: Beyond Thunderdome. A PEOPLE reporter found him sitting by himself on the set, drinking beer and spitting into the dirt. "I don't want to be doing this interview," he said. "I don't even want to be doing this film. It's a piece of s--t."

In the mid-'80s, Robyn persuaded him to take a year and a half off. Gibson bought a spread in Australia and learned to raise cattle, which he still does there and on his 20,000-acre ranch in Montana. But according to Gibson biographer Wensley Clarkson, when the actor returned to movies to begin the Lethal Weapon series, his alcohol problem flared up again. By 1991, Robyn had pressured him into getting help from Alcoholics Anonymous.

Though these days he likes to visit Manhattan clubs, and has been seen with a champagne glass in his hand, Gibson is clearly no longer a hellion. "I realized that I had used alcohol as a prop," Gibson has said. "I'd missed out on the joys of being a parent." Now he's making up for it. Gibson brings his children--Hannah, 16; twins Christian and Edward, 14; Willie, 12; Louis, 9; and Milo, 6--on location, enrolling them in local schools for long shoots. And the family is often spotted on the beach in Malibu, where they own two houses.

In 1994, Gibson bought a 27-room Tudor-style mansion on 77 acres in tony Greenwich, Conn., for $9.25 million. He installed a security fence--which, to the consternation of the local horsey set, cut off access to several riding trails. He has also spent more than $800,000 to remodel the kitchen, add a screening room and make other improvements. The stone-and-timber house "is absolutely stupendous," says a local real estate agent. "You feel like you want to entertain in this house."

Then again, prospective guests should be aware of his notion of hospitality. Last month, the moment Julia Roberts arrived on the set of the thriller Conspiracy Theory, Gibson sent an assistant to welcome her with a gift-wrapped box done up in pretty bows. As the actress walked to her dressing room, she eagerly tore the present open to find . . . a freeze-dried rat. Says director Richard Donner: "We got a shriek that brought security and two cops running." Little Mel at 40, happy at last.

-- GREGORY CERIO