Jean Smart worriedBabylonwould be 'X-rated': 'No one is going be able to come and see it'

‘How are they going to make this?’

Smart remembers thinking, after reading the 180-page script.

Babylonwas such a massive undertaking, its cast didn’t even know if it could be done.

From a runtime perspective, the film is long, clocking in at over three hours.

But it’s also a tale of outsized ambition and outrageous excess that follows multiple characters in early Hollywood.

“Honestly, I thought this movie just can’t be done.

And I even started thinking of CGI situations, I don’t know, faking it.

But, then everything was for real.

Everything was right there.”

“I remember thinking what Diego said: How are they going to make this?”

And secondly, it just seemed, yeah, that it couldn’t be done," she said.

“It was really ambitious and it seemed larger than life,” he says.

So it was really cool to get to manifest it and for it to happen."

Watch more in the video above, and check out thefull conversation here.

Babylonhits theaters Dec. 23.