"Every adult has a child-like soul," says 73 year-old Andrei Konchalovsky.

And as the co-writer/director of "The Nutcracker in 3D," Konchalovsky called upon his inner child to muster the enthusiasm and optimism to get the long-delayed project to the big screen -- after 40 years of trying.

The Russian theater and film director has modernized the classic tale, which enters wide release in the United States on Friday, by bringing it out in 3D. He also changed the setting and some of the characters.

Elle Fanning stars as nine-year-old Mary, who receives an enchanted nutcracker as a gift from her eccentric Uncle Albert, played by Nathan Lane. On Christmas night, the Nutcracker (Charlie Rowe) comes to life and leads her to a kingdom of living toys threatened by an evil Rat King (John Turturro).

Konchalovsky wrote the first version of the script for director Anthony Asquith in the late 1960s, but when Asquith died "the script went to oblivion," Konchalovsky told Reuters.

More than 25 years later, in 1995, Konchalovsky decided the time had come to make a film for his children and grandchildren, and he remembered the shelved script.

Instead of attempting to film a ballet because "film kills ballet," Konchalovsky turned to German author E.T.A. Hoffmann's original story and Russian composer Pyotr Tchiakovsky's music.

He shifted the setting from the early 18th century to 1920s Vienna, allowing him to draw inspiration from sources as varied as Gustav Klimt, Sigmund Freud, the Futurism movement and Albert Einstein -- the model for Layne's Uncle Albert.

The other major modification was to transform Hoffmann's mice into rats. "Humans have this resentment of rats, so I thought rats would be much better for the film," he said.

PINK FLOYD RATS

Konchalovsky dressed his anthropomorphic rats in military uniforms inspired by Pink Floyd's concept album and film "The Wall," but he tempered this grim aesthetic by casting comic actor Turturro as the Rat King.

"I didn't want to make the film repulsive," said Konchalovsky. "I had to make it a tongue-in-cheek character."

For every villain, there must be a heroine, and Konchalovsky found his in Fanning, the younger sister of Dakota Fanning, who in her own right has worked in films including "The Curious Case of Benjamin Button"

"She is an extraordinarily talented girl -- extraordinary intuition, very feminine, very childish and at the same time very mature," the director said.

Despite the strong cast, financing his unique vision of the Christmas classic wasn't easy as he made the rounds of film executives singing songs, showing set designs, describing his unique vision. Finally, he says, he found people "mad enough to give me money!"

As an independently-financed and distributed feature, the film is "like a David against Goliath in the market" against movies like Warner Bros' "Harry Potter and the Deathly Hallows: Part 1" and Disney's "Tangled," according to Konchalovsky.

Still, he feels that the 40-plus-year road he traveled to arrive at "The Nutcracker in 3D" has been worthwhile.

"The most happy moment I can tell you was when I brought my son to the set, and he -- a five-year-old boy -- saw the rats marching down the steps of the rat palace invading the city, he ran in front of them, into the shot, and screamed, 'Fire!'" recalled the director. "He blew the take, but I was happy because he was excited. When you see a kid mesmerized, you feel you are doing something that's worthwhile for kids to see."