Let's discuss this amazing series!
Back to what you said, PG, about who's behind the box.
You're right, it's likely Mr. C because he's the one who manufactured Dougie and arranged for the hitmen to kill Agent Cooper once he entered Dougie's body. Luckily, Dougie dropped his Great Northern Hotel key in the car as Jade and he drove away. The trick went awry, so Ike the Spike had to take care of the woman behind the hitmen operation. The attempt to take care of Dougie with a gun gets botched. Karate Chop!
If you look at the timeline, Agent Cooper arrived in the NYC box before he reaches the Purple Place/White Lodge...so the Mother was on his tail, appeared in the box (and devoured the lovebirds) shortly after Cooper departed from it. Then the Mother was knocking on the door in that room at the Purple Place before he transmits back to Earth.
Or it could be Phillip Jeffries who arranged for the box...it's difficult to contextualize his role because we've only heard/seen references to Phillip from Ray and the established connection to Argentina.
Also, it's easy to forget this, but Billy Zane (I think his character name in Season 2 is Wheeler) could be the "billionaire" behind the box. It is a mystery, but my money's on Mr. C.
I finally received my copy of The Secret History of Twin Peaks by Mark Frost, so I'm sure to find some deeper insight in what we witnessed on Sunday night. I did find an alien-looking creature within the image of an owl:
Also, regarding Part 8 of The Return, listen to this section when Mr. C gets shot, played 4x its speed:
genius stuff, folks. Don't miss out!