Paul Giamatti on the ‘State Secret’ of His Holdovers Character’s Lazy Eye: ‘Just Movie Magic’ (Exclusive)

In The Holdovers, Paul Giamatti adds to his impressive résumé by playing a character with a lazy eye. 

But how does the actor pull off maintaining his eyes pointing in different directions throughout the movie? Giamatti, 56, smiles shrewdly when asked about the trick. 

“I'm not allowed to tell you,” he reveals — or, rather, doesn’t reveal — in this week’s issue of PEOPLE. 

“I'm not joking,” adds the Oscar-nominated Cinderella Man star. “It's a state secret. I've been sworn to secrecy.”

It was Alexander Payne, director of The Holdovers, who conspired with Giamatti to keep the secret of this actorly flourish. “Alexander's enjoying the fact that people are wondering so much how we did it,” says the actor with a grin. 

“He and I just say it's the magic of acting in cinema. That's what it is. It's just movie magic.”

Giamatti’s character, Paul Hunham, is an exacting classics professor at fictional boarding school Barton Academy. Along with two fellow lost souls, played by Da’Vine Joy Randolph and Dominic Sessa, he’s left behind during the holiday break on their snowy New England campus. 

The comically askew eyes, as well as professor Hunham’s trimethylaminuria — a rare genetic condition also called Fish Odor Syndrome because of the unpleasant smell it generates — were “important [parts] of the character,” the Billions star tells PEOPLE. 

“It makes him more marginalized because the kids make fun of him about it,” he says of poor Hunham, who he describes as “a strict but well-meaning guy” not unlike the prep school teachers of his own youth. 

Before attending his father’s alma mater for both undergraduate and graduate degrees, a teenaged Giamatti attended a boarding school “very similar” to the one in The Holdovers, he recalls. “There's a wealth of stuff I'm drawing from my own past with this character.”

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

It helped that Payne and screenwriter David Hemingson made Hunham a veritable genius about Roman antiquity — a subject Giamatti himself loves reading about. Although playing The Holdovers’ intense emotional beats “wasn’t easy,” the actor admits, “some unconscious part of it was kind of gliding along nicely.”

“Paul and I share a genuinely unique — unique in my experience, anyway — sense of what movie we’re making,” says Payne, who last directed Giamatti in 2004’s Oscar-winning Sideways. 

“He can do both comedy and drama — often and at the same time — and he makes even bad dialogue work, so he’s even better with good dialogue,” the filmmaker tells PEOPLE. 

What was reuniting with his director after almost 20 years like? Giamatti says the two shared “a completely crazy shorthand,” hardly needing communication between takes. 

“You just end up having a good time with the guy and you happen to be making a movie with him,” the Emmy winner adds. “He just gave me a big old gift with this thing.” 

On Wednesday, the National Board of Review announced their honorees for 2023’s best films and film artists. For The Holdovers, Giamatti was honored with the best actor prize, while Randolph won for best supporting actress — a title she’s also earned at the New York Film Critics Circle Awards, Atlanta Film Critics Circle and multiple film festivals. 

Because they both honed their craft at the Yale School of Drama years apart, Giamatti says Randolph was another collaborator on set he immediately felt effortlessly in sync with. “I think that we're very similar in some ways,” he says of his costar. 

But, he adds without hesitation, “She’s a better actor than me.”

The Holdovers is in theaters now.