"Give a man a mask, and he will show you his true face" Oscar Wilde

Never forget this was filmed in a Rothschild mansion in England.

Those mansion scenes were the most terrifying stuff I've seen in a non-horror film.

I once read that Red Cloak could have been as many as 20 people, which is a reference to Phil doing 20 years in the can. This film was so ahead of its time.

Even though it is only a movie, I felt so embarrassed for Tom Cruise's character when he removed his mask.

Reading these comments from the past is so crazy. Turns out this was all real. absolutely mind blowing

This film still scares me - more than most horrors ever did

Red Cloak has a poncy accent. Zeigler has a distinct New Yorker upper Westside Jewish accent.

god that chanting mansion scene still gives me the creeps

The scariest part about the film is that it’s real

Victor was the man in the balcony terrace section of the open ball room. He's the one who recognized Bill off the bat and informed the higher ups of his presence as an outsider. But, I do think Victor emulates Red Cloak and subconsciously longs to be him and have his powerful position. That's why he mimics his gestures on the pool table. Perhaps to even scare Bill into making him think he IS Red Cloak to keep him safe and end his mission to figure out what happened.

This isn't a movie. It's a documentary

This movie is like a waking nightmare.

Also... he is warned that if he makes any further inquires, his family will suffer. He makes an inquiry at the mansion the next day,  and is met at the gate. Then the last scene his child walks away with 2 strangers...?

Here's what I think: 1. Ziegler wasn't Red Cloak, the accent gives that away. Ziegler was the guy in the sailor mask who nodded at Bill and tried to help him later (by sending a woman over to him, no doubt to bring him into a side room and make him seem less out of place).

2. Ziegler tapping things twice and mimicing Red Cloak was just subliminal messaging about how he wishes he were at that same level of power and status, but isn't.

3. Red Cloak was that Vitali guy detailed in the newspaper.

4. Leon Vitali was based on Les Wexner, the head of Victoria's Secret who has since been implicated as being at the top of a lot of the Epstein stuff (but never actually "outed" or charged in any way).

5. Ziegler was based on Bill Clinton, and if one looks hard enough you can find pictures of Bill/Hillary from a 1998 Christmas party that are dressed exactly like Ziegler and his wife at the Christmas party in this movie.

6. Bill is based on JFK Jr, wearing the same suit and long coat JFK Jr were known for wearing, and with the same exact haircut. In scenes where you only see him from behind, it looks exactly like JFK Jr.

7. Kubrick died right before this movie came out and JFK Jr died right after. I think Kubrick stepped on some toes he wasn't supposed to, and JFK Jr also ran afoul of the wrong people (maybe by rejecting them).

8. The large amount of cut footage which nobody has ever seen since: The studio wasn't going to just not release this movie, as it was bound to make a lot of money since people wanted to see Cruise and Kidman. So instead they just slashed the movie's runtime to remove anything remotely offensive to the wrong people. There are two things that I think were cut in particular that would make the whole third act actually make sense:

8a: Kidman's character was at the party as well and had somehow become part of the whole thing, or maybe she always was. She shows signs of dissociation during the movie and clearly has some mental instability. Also the next day she talks about her "bad dream" and it sounds exactly like the party. This made no sense and was never explained.

8b: Red Cloak and friends act like Bill saw some sort of crazy business at the party that no one can find out about, lest it bring all of them down. Except...he didn't really see anything particularly crazy. Just naked women walking around and a vaguely occult ritual. Nothing that'd necessitate killing him, or cause him to be in complete mental breakdown for the remainder of the movie over what he saw. So I think that in addition to his wife being there, there were also a lot of (very) young teens or even kids in the vicinity. Nothing would be shown in terms of them being assaulted, but I think they were shown being led off into rooms and things of that nature, to let us know the depths of the depravity at this event.

9. That last scene where they just sort of let their daughter wander off with two random guys...doesn't make any sense either, unless they've become a part of the depravity and part of their initiation is to be okay with that kind of thing.

10. Kubrick was one of the most important figures in Hollywood, and would have been let in on a lot of inner circles. He didn't actually identify with any of these "fellow elites" and this movie was him shining a light on their activities without going too far with it. You can get away with a lot in the context of moviemaking and storytelling (much like comedy can effectively expose the elites). "Eyes Wide Shut" is referring to the lower classes and how blind we are to see what's right in front of us.

Just some theories. And now I'm probably on a list somewhere.

As people have pointed out, Ziegler is not red coat, he's the guy in the sailor hat, and his wife, with the tear drop, (symbolism) is next to him.
People often point out that Ziegler tried to help Bill by sending over the girl at the orgy, and that he also may have had influence in Bill being allowed to leave with only a warning.  This is consistent with Bill "saving Ziegler's ass" earlier in the movie, and even though Ziegler's a piece of crap, he probably had some sense of honour towards a brony who'd really helped him out.
Also, I think that the Ziegler party was largely a recruiting party, and he was bringing Bill and Alice in because they were young, horny and of the correct moral disposition.  The real red coat, that Hungarian guy, had already taken a liking to Alice.  And Bill was about to break through with the two model/hookers.  Had Ziegler not screwed it all up by ODing his mistress, both Bill and Alice would have been nicely initiated, and likely would have ended up at the mask party as invited guests.  So Ziegler felt responsible about screwing up that aspect of it too.

On the red pool table there are 11 balls,the same number of women who surround the red clock,in a sense he is playing with both of them.

The line, "Life goes on, until it doesn't" is so creepy

Kubrick dies and then this film gets massively edited about 20mins worth

The red pool table is so unusual it must be a hint for us, plus the two knocks he makes with the ball.