Jake Gyllenhaal’s Race against Time

One thing Gyllenhaal can count on with Atticus: the dog isn’t hanging with him because he’s a movie star. That’s important to a man who says that,in choosing roles to play onscreen and people to be in his life offscreen,he’s looking for the same thing. “I can smell when it’s not real.” Gyllenhaal says. “I can feel it. It has to feel real. Otherwise it’s a waste of time.”

That concern is perhaps a natural priority for a man who grew up with the make-believe : his parents are director Stephen Gyllenhaal and producer/screenwriter Naomi Foner,and his sister is the actress Maggie Gyllenhaal.

“I was brought up in a family that desperately wanted to tell stories,” he says. “It was almost like a traveling circus.”

Gyllenhaal’s latest story is the time-travel thriller Source Code. He plays Colter Stevens,an agent who uses a “time pod” to go back in time—into the body of someone else—to prevent the horrific bombing of a Chicago commuter train. The twist: he can go back repeatedly,but each trip affords him only eight minutes in the past,which isn’t much time to identify the unknown terrorist and avert the bombing.

Gyllenhaal says that the idea of doing a thriller appealed to him. “I loved that it was a film filled with twists and turns,” the actor says. “The deal is that this guy is transported onto that commuter train for only eight minutes at a time to find the bomber. Each time he is sent back for his next eight minutes,the film reveals another layer.’’

“In most films the audience is way ahead of the story,Gyllenhaal says. This was unique in that it leaves you guessing. The script gets there before the audience does.’’

Gyllenhaal grew up in Los Angeles as a Hollywood baby,and made his big-screen debut as the son of Billy Crystal’s character in City Slickers (1991). “It was crazy to be a kid on a major movie set,’’ he says. “I couldn’t believe that I was that close to Billy Crystal.’’ He went on to such films as A Dangerous Woman(1993),October Sky (1999),The Good Girl (2002),gradually ascending from good child actor to good young actor and,finally,to good actor.

It was Ang Lee’s Oscar-winning Brokeback Mountain (2005) that made him a star,as he and Heath Ledger played cowboys who maintain a secret gay relationship. Ledger died a few years later,and Gyllenhaal softens when asked for his memories of his co-star.

“I remember seeing him after we were both cast,’’ he recalls. “We were at this party,and we didn’t have real space to talk,but somehow we found a little corner and we started doing some of the lines. We both thought the story was so beautiful,and we wanted to service that story in whatever way possible.’’

With stardom has come the glare of the spotlight,most notably turned on his romantic life,which besides Witherspoon and Swift has included an on-and-off relationship with Kirsten Dunst in the early 2000s.

That scrutiny comes with the job,Gyllenhaal says,but he doesn’t have to like it.

“As an actor,it’s not ideal for the press to focus on your private life,’’ he says. “I don’t like having my life played out in the media. At the same time,I completely understand the interest in an actor’s personal life.’’

“I act,’’ Gyllenhaal says. “That’s what I love to do. But I don’t want to live my life in public. Why can’t I just make great movies?’’

The most significant woman in his life at the moment,the actor adds,is Ramona Sarsgaard,his 4-year-old niece,the daughter of his sister and her husband,actor Peter Sarsgaard. She’s charming enough,it seems,to make one of Hollywood’s most eligible bachelors think about settling down. “Family is the most important thing to me,’’ Gyllenhaal says. “I have a new perspective on spending time around the dinner table with the people who are special.’’ Cindy Pearlman