Nicole Kidman and Aaron Eckhart go down the ‘Rabbit Hole’ together

Nicole Kidman is pouring Aaron Eckhart a cup of coffee and trying to remind him how they met. “At a party? It was one of those things in New York where you pass in the night? Stop! You know where we met!” Eckhart shakes his head in bewilderment, a twinkle in his eye.

There’s the easy camaraderie here of people who have experienced some living together, and indeed they have — Eckhart and Kidman play spouses and consorts in grief in the drama “Rabbit Hole.” As Becca and Howie Corbett, suburban New Yorkers who have suffered the death of a child, the two actors embarked on a harrowing, human and at times even humorous journey together.

“Two people who’ve been together for so many years get blindsided by this complete tragedy and they suddenly don’t even really know each other,” says Kidman, as she and Eckhart linger in a Los Angeles hotel suite before a night of multiple screenings and Q&As to spread the word about the film. “They’re trying to stay together, and they don’t really know how to do it.”

Kidman has received a Golden Globe nomination for her performance as the stoic Becca, who refuses to feel her grief, and Eckhart is garnering some of the best reviews of his career for his work as the raw Howie, who won’t let go of his pain. Dianne Wiest, Tammy Blanchard, Sandra Oh and newcomer Miles Teller are also in the cast.

Kidman, who won an Oscar for her portrayal of Virginia Woolf in “The Hours” and was nominated for another for her performance in “Moulin Rouge,” is no stranger to the whirl of award season. But this is the first time she’s navigating it as a producer — “Rabbit Hole,” an adaptation of David Lindsay-Abaire’s Pulitzer Prize-winning play, is the debut movie from her Blossom Films production company.

“I read it and loved the material,” Kidman says. “That was 41/2 years ago. It’s been a long road to try and get it made. But that’s OK. I don’t mind. That seems to be the time period it takes to get difficult films made.”

After the actress optioned Lindsay-Abaire’s play, one of her first tasks was to help cast the challenging role of Howie. This movie’s biggest surprise is the humor it finds in grief (one scene has a stoned Howie giggling through a group therapy meeting), and the actor who played this character would have to be equally deft at both tragedy and comedy.

Eckhart’s career has been a study in darkly comic roles, including the chauvinist pig he played in “In the Company of Men,” his motormouth tobacco lobbyist in “Thank You for Smoking” and his hero-turned-villain Harvey Dent in “The Dark Knight.”

“I’d seen him in so many things, and I did always want to work with him,” Kidman says. “So I called him and asked him to be my husband.”

For Eckhart, Kidman’s call was an opportunity to latch on to a passion project with promise. “Nicole’s starring in the movie and producing it,” he says. “It’s incredible material. I figured she was going to go to the wall with it, and I wanted to be along for the ride.”

Once the under-$5-million budget was raised and preproduction got underway, Kidman weighed in on subjects generally beneath the concerns of a leading lady. The first order of business was getting cast and crew situated at the Queens, N.Y., house that would serve as the Corbett family homestead. “As producer, I was like, ‘We’re going to need a Port-a-Loo, cause the sewage system in this house won’t survive a whole crew and all of us,’” Kidman says. “I thought I was really clever.”

But it was an actorly concern for her costar that drove Kidman once Eckhart arrived on the set. “I was committed to being completely available and open to Aaron so that he knew he had somebody to confide in, that he could trust and hopefully felt safe with, so that we could go on this journey together,” she says.

Before cameras rolled, the couple had a few days alone in the house with their director, John Cameron Mitchell. Sitting on the floor — the home had not yet been set-dressed — they improvised some scenes and got comfortable. Kidman took a bath. “We lived in those rooms, with paper-thin walls,” Kidman says. “Which is really good. You’re living together and you’re seeing each other in very close confinements, which doesn’t happen when you have a bigger budget and you go off to your trailers. You’re just not as tight.”

The roles required both actors to travel to shadowy places in their psyches. “As an actor, it’s sort of what you pray for,” says Eckhart. “It’s an opportunity, not a curse. It’s fun to emote and to yell and to cry. And it’s fun to have somebody to yell at who knows how to take it.”

For Kidman, whose character keeps her pain far more contained for much of the film, Becca’s fears and sorrows surfaced off the set. “I’d have unbearable nightmares where I’d wake up absolutely sobbing. I think I’m handling it, and it comes out that way. Some people have said, ‘You must be a masochist.’ No, not at all, but I’m committed to understanding the human condition. It makes me a kinder, more compassionate person when I can live and try to absorb these things.”

Now that the film is wrapped up, one of the most difficult tasks lies ahead — finding an audience for a movie that asks the viewer to contemplate the unthinkable. “I want people to see this movie,” says Eckhart. “That’s why you make movies. It’s about a family; it’s everything people like to see. It’s just, will they go see it?”

Some of the film’s earliest viewers were members of the child bereavement group Compassionate Friends, which is hosting candlelight screenings. “That’s why we went to the places we went, to try and honor and do justice to these emotions,” says Kidman. “My hope is that for some people, it will make them feel not so alone.”

rebecca.keegan@latimes.com