©AP / Zachary Quinto

NEW YORK (AP) — On a wall in Zachary Quinto‘s dressing room is one of his most prized possessions right now: a picture that looks like a child’s ink drawing.

It’s of a wolf, or maybe a big dog, looking over its shoulder. The lines are shaky and uncertain. There’s something haunting about it, maybe even foreboding. It’s dated Nov. 10, 1986.

“It helps me so much,” the actor says.

It was drawn by Rose Williams — playwright Tennessee Williams’ sister, who underwent a lobotomy as a young woman and was institutionalized for the rest of her life.

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For Quinto, looking at that picture every day is like having a direct line to Tennessee Williams’ soul, pretty crucial as he makes his Broadway debut in the playwright’s “The Glass Menagerie.”

It’s a meditation on guilt, with a shy, lame young woman at its center. Tennessee Williams based the character on his sister, a woman whose fate gnawed at him.

“That lineage of pain is superimportant,” says Quinto. “It’s something that Tennessee never got out from underneath his whole life, as successful as he was. I think it was something that truly haunted him.”

As you might guess, Quinto, 36, is eagerly going the extra mile with his research. The “Star Trek” star had always wanted to be on Broadway and is savoring his arrival.

“I was walking to work today. I’ve been walking the past few days because it’s so beautiful out, so I walk from downtown. And I was like, ‘This is my life’ living in Manhattan, a dream I’ve always had, and I’m walking to my theater on Broadway to do Tennessee Williams. It’s not lost on me. I really am humbled by it often. I feel really grateful.”

In the play, Quinto plays Tom Wingfield, a restless warehouse worker who dreams of escaping his overbearing mother and cripplingly shy sister. Tom narrates the action looking back, like a memory.

This revival by the American Repertory Theater was a hit in Boston. It co-stars Cherry Jones as Tom’s mother and Celia Keenan-Bolger as his sister. It is directed by Tony Award-winner John Tiffany.

Producer John N. Hart, behind such hits as “Once” and “Chicago,” says Quinto is a “revelation to watch” as he spars onstage with Jones, bringing the humor out. Some critics have said Quinto is perhaps the best Tom ever seen. “He does it brilliantly. I think people will come to see him as a star,” says Hart.

Quinto took the long way to get here: A graduate of Carnegie Mellon University, he dreamed of a life in the theater. So he went to Los Angeles to first build a name for himself.

“The commercial theater landscape has become as driven by revenue as any box office of any film that opens. It’s driven by name value in a way that certainly isn’t used to be in the generation previous to mine,” he says.

“But it’s an inevitability and it’s something that I recognized when I was coming out of school and looking at film and television actors who had never done theater headlining Broadway shows.”

So he decided to play Hollywood’s game — snagging parts in TV shows like “24,” ”Heroes” and “Six Feet Under.” Then he got the role of Spock in J.J. Abrams’ rebooted “Star Trek.”

“It was always a means to an end to me,” he says. “I always felt like I wanted to be in L.A. so that I could come back here and do theater and now I’m making good on that promise to myself.”

Quinto has been canny about approaching the clubby world of New York theater. He first made his bones — and proved his stamina — in 2010-11, tackling a celebrated off-Broadway production of “Angels in America,” a two-part play that totaled some four hours each.

“I didn’t want to come in, swoop in with my name above the title of the play like I was some Hollywood entity,” he says. “I’ve been doing theater since I was 10. Theater’s my jam. It’s my life, ultimately. If I could make a living just doing theater, I feel like I really might.”

The job that pays Quinto’s bills — “Star Trek” — is on a break right now. Abrams’ attention has been diverted to rebooting “Star Wars,” so plans for Quinto’s next appearance as Spock are cloudy.

Quinto signed up to do three episodes and says he’s starting to get recognized on the street, despite his headphones, sunglasses and keeping his head down — “like every other New Yorker.”

He consulted with Leonard Nimoy, the previous Spock, about how taking on such an iconic role can be risky, but decided to see it as a challenge and trusted that things had changed.

“I frankly think our attention spans have dwindled so alarmingly that people aren’t necessarily as keen to inextricably associate an actor with a character as they used to,” says Quinto. “It’s a different landscape now. The metabolism for entertainment is so much faster that it doesn’t linger like it used to.”

Quinto, who earned an Emmy nod this year for playing a psychiatrist on “American Horror Story,” has also smartly created a backup plan in case everything falls apart: He and a few friends from Carnegie Mellon created a production company that had success with “Margin Call” and is about to release Robert Redford’s next film, “All Is Lost.”

A Redford film, an Emmy nomination, a mega-movie franchise and now a Broadway show. “I couldn’t be happier. I couldn’t be more grateful for where I am at this moment. That’s not been something I’ve always been able to say,” he says.

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