“It would have been as expensive as the train by the time we were done,” Christopher McQuarrie says.

Warning: This article contains mild spoilers for Mission: Impossible — Dead Reckoning Part One.

Julia Roberts could have played a very important part in Mission: Impossible — Dead Reckoning Part One as one of the brunette women Ethan Hunt (Tom Cruise) just can’t seem to keep alive, no matter how hard he tries.

In a new Empire Spoiler Special film podcast interview, director/co-writer Christopher McQuarrie revealed he considered casting Roberts and digitally de-aging her to play a role in the flashback scenes that show how Ethan and villain Gabriel (Esai Morales) are connected.

In the past, Gabriel murdered Ethan’s girlfriend Marie and framed him for her death. In the film, Marie is played by Mariela Garriga, but McQuarrie reveals that he originally wanted to cast a megastar from the time period of the first Mission: Impossible film.

Tom Cruise in ‘Mission: Impossible — Dead Reckoning Part One’; Julia Roberts. PARAMOUNT PICTURES AND SKYDANCE; THEO WARGO/GETTY IMAGES

“If you hire Esai Morales and Tom Cruise and de-age them, and then hire some 23-year-old woman to be their confidant in Berlin in 1989, that’s bulls—,” McQuarrie said. “We started looking at it and saying, ‘Who’s Marie going to be? Who from that era would Marie have been?

It would be Tom in, say, 1989, it would be Tony Scott’s Mission: Impossible — that’s who would have been directing the movie before Brian De Palma in that era…

I looked back at who was the ingenue, who was the breakout star in 1989? And right around then was Mystic Pizza, and I was like, ‘Oh my God. Julia Roberts. A then-pre-Pretty Woman Julia Roberts as this young woman.'”

The director goes on to explain that the only way he “could have seen doing the sequence justice was to somehow convince Julia Roberts to come in and be this small role at the beginning of this story.”

He originally wanted the flashback scene to be longer as well, but ultimately decided it would be too distracting for audiences to see Roberts, Cruise, Morales, and Henry Czerny (who plays former IMF chief Eugene Kittridge) looking almost 30 years younger via digital de-aging visual effects.

“The best de-aging I’ve ever looked at, all I kept thinking is, ‘Wow, this de-aging is really good.’ I’m in no way, shape, or form connecting to the story,” he said. “As you’re conceptually going through it, you’re like, ‘Now all anybody’s going to be doing is thinking about the de-aging of Julia Roberts, and Esai, and Tom, and Henry Czerny.'”

There was also a much simpler reason why McQuarrie decided against the idea: It cost too much money.

“I got the bill for de-aging those people before their salaries were even factored into it,” he said. “And if you put two of them in a shot together, or three of them in a shot together, it would have been as expensive as the [massive third act action scene set on the] train by the time we were done.”