New York ? One recent Monday at 8:30 p.m., Patrick Stewart found himself with nothing to do.

He didn’t have to go to work – his play “Macbeth” was closed for the night. And Stewart, who has earned raves playing the doomed Scottish king, had not made any other plans.

“I did actually think, ‘This is the saddest thing.’ Here’s a leading actor in a Broadway show on his night off and he’s sitting at home on his own. Nobody to see, nothing to do, nowhere to go. What am I going to do?”

Then his eyes fell on a copy of “Hamlet.”

So Stewart cracked open a bottle of good Napa wine and settled down to reread another Shakespeare tragedy.

“It just turned into the greatest evening,” says Stewart, wistfully. “After 50 years, it still takes my breath away.”

During a conversation over soup and salad before a recent performance, one thing becomes abundantly clear: Stewart is a hard-core Shakespeare freak.

He’s a man who memorized Shakespeare for fun as a teen and spent 14 years with the Royal Shakespeare Company. He never abandoned The Bard despite commanding a star ship for seven years on TV’s “Star Trek: The Next Generation.”

Even on vacation he can’t let go: Stewart, who managed to slip away to the Caribbean for a few days before “Macbeth” debuted on Broadway, found that the misty moors followed.

“I was walking along the beach muttering the lines,” he says, laughing.

There’s little tropical heat in Stewart’s “Macbeth,” an updated, hair-raising interpretation that reeks of Stalin and Orwell. The single set and Soviet-style uniforms are augmented by a supernatural freight elevator, video projections and a kitchen sink – for Lady Macbeth to wash the gore. The Three Witches even rap.

Stewart, 67, who has grown a vaguely unsettling mustache for the part, portrays a Scottish king more Hamlet than Richard III – introspective, analytical, thoughtful, questioning. It’s his first Macbeth.

“Nearly 50 years I’ve waited,” says Stewart. “I learned it when I was 14. I memorized all the soliloquies just because I thought they were great. And they stuck, so I didn’t have to learn those bits of the play, which is a blessing, because learning lines has now become the one curse of this job.”

The production, under the direction of Rupert Goold, debuted in May 2007 at England’s Chichester Festival Theatre, switched to London’s West End and then moved to the Brooklyn Academy of Music before transferring to Broadway.

Stewart’s performance has earned him some of the best reviews of his career. The Times of London said his Macbeth “is an enthralling creation of frailty, appetite, egotism and grim humor.” The Daily Telegraph said he had turned in “a truly great performance.”

His Lady Macbeth agrees. Kate Fleetwood, who is married to Goold, has found Stewart to be an actor of incredible energy and a playful leader of the company.

“I think he’s invigorated by his successes over the past couple of years,” she says. “The sweetness of what he’s achieving now is all the more sweet because he’s put the work in over the years.”

Raised in Yorkshire, England, Stewart joined an amateur drama group at 12 and later won a scholarship to the Bristol Old Vic Theatre School, launching a career as a character actor.

“What I’m doing now is all I ever wanted to do. I didn’t have any other ambitions,” he says. “Once I’d been accepted into the Royal Shakespeare Company in 1966, I was perfectly content.”