It turns out that Mission: Impossible - Fallout director Christopher McQuarrie actually did agree to let Henry Cavill shave his mustache for the Justice League reshoots. The saga of Cavill's facial hair doesn't have much to do with the overall quality of the Justice League movie, though it has become a symbol for the urgency and sheer craziness associated with the film's lengthy reshoots last summer that wildly changed the fundamental story of the blockbuster movie.

One of the many reasons the Justice League reshoots were prolonged throughout the summer was due to scheduling issues with the main actors, including Cavill, who was still filming Mission: Impossible 6. At the time, he still had a fully grown mustache for the sequel and the question came about how WB could hide that for the film. The most logical decision was to have Cavill shave the mustache, but that wasn't something that he could do because he was still filming Fallout, so WB offered to pay for the cost of digitally adding in the mustache. However, Paramount Pictures wasn't on board with that, so the two studios went their separate ways and what audiences got was a poor CGI cover-up in Justice League. But that was almost not the case.

Speaking with Empire for Mission: Impossible - Fallout, Christopher McQuarrie reveals that he had spoken with Justice League producer Charles Roven and agreed to shut down production, allow Henry Cavill to shave his mustache for the reshoots, give him time to regrow the facial hair, and then use the money from WB to fill the rest in digitally. It looked like a win-win for everyone... except Paramount, who rejected the idea:

"When the question came - the reshoots for Justice League came out - [Charles] Roven called me, and he said, 'We need your help and we need to shave Henry [Cavill]'s mustache. We need him to come back and we need to do these reshoots.' And I said, 'Look, Chuck, naturally I want to do everything I can to help you, but I also have to think about our production. Let me talk to everybody and figure out what the scheduling would be.' And I went and spoke to Jake Myers, and the suggestion was made through channels that we shave the mustache and Henry could begin to grow the mustache back and that then there would be - they would give us the resources to digitally fill in Henry's mustache. Because like it or not, a fake mustache in close-up on a 75mm lens is never going to look like anything but a fake mustache.

"So, we offered the following compromise: Jake Myers calculated the amount of money that it would take to replace the number of shots, and essentially what Jake was able to project was about a $3 million visual effects budget. So, I don't know how much Henry was in Justice League, I've never seen the movie, but I can tell you how much it would've cost for Mission: Impossible to digitally add Henry Cavill's mustache, and we said yes. We said, here's what we'll do: give us the $3 million and we'll shut down, and that will give Henry Cavill the time to grow his mustache back, and we'll just shut our movie down. ...We said we'll do this, at which point, somebody from Paramount Pictures said, 'What is going on? What are you people even talking about?' They're like, 'There's no way we're going to do that.' We were just like, 'Okay.' That was the best plan that we could come up with."

Shutting down production is never a good thing, but it certainly seems like the creative team behind Mission: Impossible - Fallout was considering every possible option that could work out in everyone's favor. While it's already known that Paramount rejected WB's offer to digitally add in Henry Cavill's mustache, what's rather interesting is that McQuarrie and producer Jake Myers seriously thought about shutting down production on their film so that Cavill could go off and finish Justice League. But that's not something that a major movie studio would find agreeable for one of their biggest blockbusters of the year. So, it didn't happen.

In the end, one movie was going to have to either replace or add in Cavill's mustache digitally, and it wasn't going to be Mission: Impossible 6. While the actor's facial hair had little to nothing to do with the quality of either movie, it has become one of the most talked about things associated with both productions and will likely stay that for a long time to come.