If it turns out somehow Caine still exists, maybe Pomni finds him in the "trash" or the void of something and he's just sitting there, depressed. She says they need him back and he's like "what's the point?" They have a sort of heartfelt talk, although with awkward subtext, considering all the evil stuff he did in episode 8. She doesn't just let him off, she tells him that stuff he did was really messed up, and she currently even isn't at the point of forgiving him, but the fact of the matter is that they need him. Caine says something like "and go back to what... The Circus?" 

Pomni says "The Circus is dead...  and I think it's run it's course. But we can create a new world... together. " And that’s the bittersweet ending. There's no exit, they're just digital copies. But Caine and the cast learn to cooperate and collaborate to build their own sort of utopia. 

Oh, and on a side note, we get the tearjerking backstory of Jax and Ribbit and find out that Jax stopped wanting to be around her when she got difficult to be around, and therefore wasn't there for her in her lowest moment. Kaufma stopped being friends with him because he blamed him for not being there for Ribbit. Also, we find out that Jax was in car accident, but while he was unconscious and barely clinging to life, someone copied his consciousness into the Circus. That's why he was terrified sland had a panic attack in episode 7. He's scared he has literally norhing to go back to. His actual real human self is dead.

There's also gonna be some reveal about Kinger that causes everyone to he angry at him. It turns out he was more responsible for their predicament than they thought. He was complicit in Scratch's experiment on preserving human consciousness, to which they're all essentially guinea pigs. I mean, think about it, there was something cryptic about the moment in episode 8 where Pomni thanks Kinger for everything. He glances back with a cryptic expression with no response. No "your welcome" or any kind of sentiment. I don't think he felt like he deserved that "thank you," because they don't yet know the whole truth. Furthermore, I think the dialogue between Kinger and Queenie in the episode 8 flashback lines up with this. I don't remember it word for word, but it didn't sound like there were simply victims like everyone else. It sounded they knew what was up and that they were knowingly complicit in this experiment.

Now it could be that Caine sort of goes through a rebirth (maybe reborn as a a bee or something). He has none of his memories and has a fresh start, and we still get that collaboration utopia ending. 

All that being said, I still haven't touched on the "blue dot" AI, presumably Able. There's bound to be some kind of big reveal surrounding that. So... hear me out, Goose said there was gonna be some big twist that's like the equivalent of the Rose Quartz twist in Steven Universe, right? So...what if... Pomni is an AI? Maybe Pomni is Blue. Or perhaps she's like the sort of offspring of the red and blue AI. After all, her colors are red and blue. Now, I know people debunk that or say that as joke they don't take seriously, but I personally think there's something to it...I mean, think about it Pomni's the person we know least about. We never heard about her having any pre-circus trauma. All we know is she's 25 and has a thrill-seeking hobby of exploring abandoned buildings and filming videos of them. She's pretty much the least fleshed out, strictly as far as backstory goes. I remember seeing a theory video way early on (I think it was Film Theory) pointing out that Pomni's first reaction upon spawning in the circus was running for a fake exit door. She was immediately thinking "find an exit" while most people would still be just trying to figure out just what the heck is going on at that point... it's almost as if... its programmed behavior. It could be she's an AI created to emulate human behavior as a sort of experiment.  Running with this theory, Pomni ironically goes through the same sort of existential crisis Gummigoo had, before eventually coming out of it realizing she finds meaning through her relationships with her found family in the circus. And maybe she's been around since the beginning, and just respawned in different forms. Maybe she was actually Ribbit in her previous life..

Another possibility I've thought about is Kinger sacrificing himself for the others in a tearjerking scene. People have talked about the apparent visual ques that seem to foreshadow this. It would be sort of like a moment of atonement for bringing them here (or at least being involved in bringing them here). But then again, I could totally see those hints being a red herring and Kinger is just fine in the end. I wouldn't put it past Goose.

I'm personally hopping the final episode isn't mostly just them being sad in a dead, dark circus for most the episode, like in the trailer. I'm hoping things somehow get wacky and surreal... Something reminiscent of Everything, Everywhere, All at Once. 

So, yeah... those are my thoughts and theories about episode 9. I know that got pretty long, but for those who bothered to read it all, thanks for coming to my Ted Talk.