'Peter Pan Live!' stars Allison Williams, Christopher Walken and Christian Borle preview NBC's second big musical event.

The Peter Pan Live! Cast Talks Flying, Hate-Tweeting and Dressing in Drag

Peter Pan Live! Preview NBC

If your fingers are already itching to Twittersnark the heck out of tonight’s Peter Pan Live!, star Allison Williams can save you a lot of trouble and furious hashtagging: You’re going to loathe it.

Peter Pan you cannot watch cynically. If you do, you’re gonna hate it,” the Girls star says at a press event that takes place while the production is in rehearsals. “There’s no question. It falls apart instantly.”

But Williams thinks Peter, a little boy has the chutzpah to go up against Captain Hook, can easily dispatch with the kind of negative talk that dogged The Sound of Music Live! last year.

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“I have full faith that this will happen: People will hear the opening strains of music that they know deep, deep, deep in their heart, and it’ll just make them nostalgic and they’ll become a kid again,” she says, smiling. “They’ll crumble. They might get one hate-tweet out, just really quickly, and then we won’t hear from them for a while.”

As was widely reported when the Girls star landed the lead in NBC’s second huge musical event, Williams has dreamed of playing the eternal adolescent ever since she was a little girl. After months of learning how to be Peter, her enthusiasm remains high and her esteem for executive producers Craig Zadan and Neil Meron — who brought Sound of Music Live! to an audience of 18.6 million for its debut, nabbing a 4.6 in the demo — is even higher.

“I trust these people to do what they do,” she says. “They do this really well.”

Read on for more scoop on the television event from Williams and co-stars Christopher Walken (The Deer Hunter), Christian Borle (Smash) and Broadway star Kelli O’Hara.

TRANSFORMATION IN MOTION | To go “from a very modern girl who has a lot of sex to an asexual, prepubescent British boy from the turn of the 20th century,” Williams says she started prepping for the part in late August. Training included lessons in swordfighting, singing, working Peter’s British dialect and — of course — “flying” via wires.

FRIENDS IN HIGH PLACES | The night before NBC announced that Williams would play Peter, she called pal and Girls co-star Lena Dunham with the news. “She said, ‘It’s so subversive! You’re going to be in drag,'” Williams says, laughing. “It was just such a classic Lena reaction.” Meanwhile, Girls ‘Andrew Rannells was rehearsing for his Broadway run as the gender-bending lead in Hedwig and the Angry Inch around the same time Williams was learning how to become Peter. “I was like, ‘We’re switching genders!'” she says. “He was so fabulous as Hedwig, and I learned a lot by watching him.”

WILLIAMS WAS AMONG THE 18.6 MILLION | Williams “was completely blown away by” Sound of Music Live!, she says, remembering how impressed she was with the nunnery set, in particular. “And then I saw Carrie [Underwood] on the hillside, and I started to cry. It was very moving to me.”

FLY GIRL | Flitting around several feet off the ground looks easy but is actually quite tough, Williams says. “It’s hard to stay forward… The way you leave the ground determines the rest of your flight, which is a little intimidating.” Still: “The most fun thing in the world is the first time you go up.”

THE ROAR OF THE CROWD | Walken, who began his career on the stage, says the absence of live feedback has been an adjustment for him. “I always find the audience teaches you things. It shows you where the jokes are, for one thing… You can absolutely feel an audience, and you know when it’s going good.”

SONG-AND-DANCE MAN | Walken praises both his co-star’s vocal prowess — “Allison can really sing” — and the fact that Captain Hook isn’t required to belt. “There’s a lot of talking-singing, which is good for me,” he says, laughing.

MEET THE PARENTS | “I’m Mrs. Darling, and I’m so mad I’m not flying,” jokes O’Hara, who plays opposite Borle’s Mr. Darling. (Borle also plays Hook’s bumbling bo’sun Mr. Smee.) The actress says she’d leaned on her co-star, who was Max Detweiler in last year’s production, to give her tips on being in the mash-up of live theater and break-for-commercials TV. Related to his previous experience, Borle adds that he was surprised when other actors took to Twitter to mock The Sound of Music Live! “I just thought, don’t you ever want to work for NBC?” he says with a laugh.