While audiences are taking their seats for “The Library,” a new play at the Public Theater written by Scott Z. Burns and directed by Steven Soderbergh, its lead actress, Chloë Grace Moretz, is already onstage.
Playing a high school shooting victim who awakes in a hospital to confront conflicting remembrances of the event, the 17-year-old Ms. Moretz spends these 10 to 15 minutes before each show lying silently on a table, trying to stay in character and tune out the frantic theatergoers she can hear in the house.
“It’s kind of awkward,” Ms. Moretz said a few days ago, adding a sarcastic roll of her eyes. “You hear: ‘Oh, we didn’t get reservations tonight.’ ‘Dinner was $400.’ And I’m like, ‘Oh my God, dude, shut up.’ ”
This is about as much as teenage petulance as one can extract from Ms. Moretz, a preternaturally poised actress with a résumé of film credits — the superhero satire “Kick-Ass,” the period fantasy “Hugo,” a blood-soaked remake of “Carrie” — and a mature demeanor to rival performers twice her age.
In an entertainment industry populated by wild Mileys, run-amok Justins and forsaken Lindsays, where the arrival of one’s 18th birthday means it’s time to lose your inhibitions, your clothes or your relevance, Ms. Moretz may be able to break this dispiritingly familiar pattern.
Her collaborators on “The Library” say she is already astonishingly equipped to handle grown-up realities and ready to be trusted with significant artistic responsibilities.
“She’s so centered and levelheaded, and clear in what needs to be done,” said Mr. Soderbergh, the Oscar- and Emmy-winning director of “Traffic” and “Behind the Candelabra.”
“I’ve seen no indication that she places herself at the center of the process of working on the play,” he added. “She’s there to tell the story.”
As Ms. Moretz, who is making her stage debut in “The Library,” put it: “I’m very confident of myself. But coming into this, I was the most unconfident I’ve ever been, which made me excited.”
On an April afternoon, she was sitting in the Public’s upstairs restaurant (also called the Library), with her mother, Teri, and a publicist positioned a few tables away, while she compared herself to other people her age.
“Seventeen-year-olds deal with, like, emotional problems,” Ms. Moretz said. “They’re flighty, and they’re confused. Everything’s a process with them.”
“I’m not saying I’m not like that,” she continued. “I’m very much like that. I’m moody, and stuff happens, and Mom can definitely tell you that’s very true.” (From her seat, Teri Moretz nodded knowingly.)
What makes her different, Ms. Moretz said, is that she can distinguish “between my life and my job, and I never mix the two.”