There's a place in Tijuana that unnerves Gael García Bernal in a way the city's seedy bars, brothels, or roach-infested motels never could. On a break from filming the movie Babel last year, the actor took a stroll in a park, only to find his way blocked by a rusty metal wall that marks the Mexico-United States border. Forty-four miles long, the barrier runs straight through an obelisk known as a ''friendship monument'' all the way into the Pacific, before eventually fading from view. ''The fence goes deep into the ocean, as if there was a kind of imaginary energy line,'' García Bernal says, shaking his head. ''Animals don't respect lines. Air doesn't. Water doesn't. And humans don't. It's not in our nature.''
Clearly, adhering to boundaries is just not in the DNA of a free spirit like the 27-year-old García Bernal. Since becoming an international star at 23 on the strength of back-to-back art-house hits Amores Perros and Y Tu Mamá También, the Mexican actor has roamed in search of parts that defy easy categorization. He returned to Mexico to play a transgressive Catholic priest (The Crime of Padre Amaro); crisscrossed South America as the legendary revolutionary Che Guevara (The Motorcycle Diaries); and traveled to Spain to portray a revenge-seeking drag queen (Pedro Almodóvar's Bad Education) . In this month's The King, his first American indie, he stars as an ex-naval officer from Texas who responds to being rejected by his father (William Hurt) by sleeping with his half sister (Pell James). ''The father-son relationship, incest the story deals with [classically tragic] issues that I'm interested in,'' the actor explains over lunch in Manhattan.
That curiosity is at the heart of who García Bernal is, according to Diego Luna, his closest childhood friend and Y Tu Mamá costar: ''He's a cool guy to be around because he's always challenging you to take [an idea] somewhere else, always asking himself questions.''
Although his string of ever more serious parts may not show it, García Bernal loves to geek out on Charlie Chaplin and Monty Python movies. So when director Michel Gondry (Eternal Sunshine of the Spotless Mind) asked him to take a quirky comic turn in the surrealist mind warp The Science of Sleep, due out this August, he flipped. ''I was like, 'Oh man, yes! Please! Let's do something funny!''' the actor recalls. As the impish Gondry says, ''Gael, he's like a machine of happiness.''
Born in Guadalajara to a pair of leftist actors, García Bernal fell into the family business by happenstance. By age 12, he was getting work on Mexican television, including a stint on the soap El Abuelo y Yo with Luna. Even when he became the first Mexican to enroll in London's prestigious Central School of Speech and Drama, it felt like a game. ''I knew I wanted to act all my life because I found it really fun to do,'' he explains. ''But I didn't know I wanted it as a career.''
His attitude changed in 1999 when he landed the role of the desperate delinquent Octavio in Perros. ''With that film, I kind of [entered] the elitist bubble of cinema,'' the actor recalls. Then, amid the acclaim for Alfonso Cuarón's racy Y Tu Mamá, García Bernal was singled out for his intensity and sex appeal. ''I don't know what makes a sex symbol, but I have neither muscles nor height, so it's nice to make it there,'' the 5-foot-6 actor says with a boyish laugh.