By MICHAEL RIEDEL
IN the new musical "The Wild Party," Mandy Patinkin gives an intense and frightening performance as Burrs, a gin-swilling, psychotic vaudeville clown who beats his girlfriend.
But for many of his fellow cast members, Patinkin's performance has at times been a little too intense, a little too frightening and a little too real.
Cast members say that during previews, the actor has ad-libbed bits of physical and verbal abuse, including smacking people in the head, shoving them, spitting water in their faces and making offensive remarks to them under his breath.
He has also been prone to strange emotional outbursts - at one point holing up in his dressing room and sobbing uncontrollably for four hours because he was unhappy with the show's lighting.
The actors say they were never sure what Patinkin was going to do to them on stage. One said they "walked around like we were wearing lead underwear for protection."
Patinkin's co-star Toni Collette got so fed up with his antics that she decided to get even. During the performance last Friday night, she crept up on him from behind and gave him a "retaliatory shove," according to a cast member.
After the performance, a furious Patinkin said he was quitting "The Wild Party." He did not show up for the Saturday matinee, prompting the producers to threaten him with a multimillion-dollar lawsuit, production sources said.
The threat worked: Fifteen minutes before the Saturday night performance, just as his understudy was preparing to go on stage, Patinkin walked through the stage door and did the show.
One of Broadway's biggest stars, Patinkin has long had a reputation for being difficult.
Even he concedes he can be flaky. At the start of rehearsals for "The Wild Party," he told cast members that "Mandy" is short for Mandel, which in Yiddish means "nut."
"And that's what I am, a nut," one performer quoted him as saying.
How nutty soon became abundantly clear, according to cast members.
During one preview, Patinkin smacked two male actors in the head and then kissed them violently on the mouth - two actions that were not part of director George C. Wolfe's staging.
Another time, while sitting at the bar on stage, he took a swig of water and then spit it out in an actress' face. The spitting had never been rehearsed or discussed, so the actress was caught off guard.
Patinkin clashed with Collette early on in rehearsals.
While working on an intense scene in which she holds a knife to his heart and threatens to kill him, he decided that instead of singing a tender song to her, he would turn to the audience and sing it to them.
A frustrated Collette finally yelled: "I'm holding a knife to your heart and I am going to kill you! Why are you singing to the audience?"
When Patinkin refused to look at her, she threw down the knife and walked out of the rehearsal room.
"You never know what he is going to do," said a cast member. "Sometimes he's nice and contrite about something he did the night before. Other times he's seething, and you have to watch out."
Patinkin's defenders say his outbursts and ad libs are part of his creative process, and that each time he has gone too far with another performer, Wolfe has spoken to him and the incident has not been repeated.
They also say that, because of its subject matter, "The Wild Party" itself has stirred up weird behavior not just in Patinkin but in other cast members as well.
"This is a violent show," said one source. "There's simulated sex, drug use, fighting and drinking. It brings out the dark side of everyone."
Wolfe told The Post: "The parameters of this material are so volatile, it has taken everybody - and I mean everybody - some time to learn what they are."
He added: "The rehearsal and preview process ... has been demanding, exhilarating and exhausting. The material requires that actors go to very complicated emotional places inside of themselves. All of the actors have gone on that journey passionately, intensely and fearlessly."
Wolfe called Patinkin "an amazing artist who has transformed the role of Burrs in ways I never imagined. He is a one-of-a-kind creative force ... I would relish the opportunity to work with him again."
Calls to Patinkin's lawyer, Victoria Traube, were referred to the show's press agent, who said the actor was "unavailable for comment."