The cycle is broken
A collection of The Sampled arrive at the pig farm. All the men are dressed in suits and the women wear nice clothes. They certainly do not look like pig farmers, but they're drawn to their pig counterparts.
Kris is front and center, prominently wearing a yellow scarf. Yellow has been the color of her struggle, and now, after she murdered The Sampler, she's ostensibly in control of the cycle. Or at least one part of it.
Kris has a shocked look, possibly because every pig there could very well have a human connection, and there are more pigs visible than people. Maybe some of The Sampled haven't even been discovered yet.
The Sampled assembled here are those who survived. No matter what happened to them with The Thief and/or The Sampler, standing here is, like it is for Kris, an act of defiance. We see Kris, Jeff, Brent, and some who received Walden at their work or house. For me, Kris's look is the oblique terror of all those unaccounted Sampled still drifting through the world, some wholly ruined by the process, some still clinging to a semblance of normalcy.
Kris went through a terrible ordeal, but she's clawed back to a position of power.
Kris and Pig Kris finally meet.
After another cut to black, we've jumped an unknown amount of time into the future in which The Sampled are now working as pig farmers.
Jeff isn't quite dressed for the job, and while there's no suggestion that we've jumped into a future where they're expert farmers, what's important is that The Sampled, for lack of a better word, won.
Kris paints the white poles yellow. The era of the "blue" is over.
A wide shot shows that about half of the fencing has been turned yellow. Combined with the new farmers' growing confident running the place, this is only just the start of something new.
A vet shows up and examines some pigs, foreshadowing an upcoming litter.
Kris and Brent talk to the vet. Kris smiles and, though it's the side of her face opposite the camera, seems to wipe away a tear. She looks away and a smile begins to form. This is far from her blank, scattered, paranoid self that we've seen for most of the film.
The end of the "blue"
An E&P worker shows up at the site where they usually find blue orchids, but there are none. Without cross-referencing the gestation of pigs and the growth cycle of orchids, it's fair to assume that both the blue-orchid collecting by the E&P people and The Thief harvesting of "blue"-centric orchids occurs every few weeks or months. Now, though, there are no blue orchids, meaning no flowers with "blue"-infected worms.
At the E&P shop, The Thief can't find the correct plants. His operations are done. This shot is held for fourteen seconds, which makes it one of the longest in the entire film.
By now, even the kids are helping him, though if it's unclear what he knows (or if he knows anything at all) about the cycle.
The kid with glasses shows a reddish plant to The Thief, but when The Thief scrapes off (or tries to scrape off) some powder from the leaves, he shakes his head.
Another cut to black brings us back to the farm and some piglets. It's unknown whether the piglets are from Pig Kris or another. In the following shots - the last in the film - Kris looks very content. It's likely she has some sort of emotional bond with the piglets.
Kris, with a new haircut suggesting another time jump, pets one of the piglets. She then picks one up that has the same coloration as the reddish-brown Pig Jeff.
Though we can't hear it, she moves her mouth while holding the piglet. Her lips don't seem to form any words, and it seems like she's making wordless sounds like she wound for an infant. She can't have human children, but if she feels as strong a pull to the pigs as she showed earlier in the film, then they're as emotionally satisfying as if they're her own kids.
Kris holds the pig against her shoulder and rocks it to sleep.
The film ends.
Whenever I think of the brainpower required to scrutinize a film this deeply, I imagine it required tenfold more thought to make it. As I've repeatedly mentioned, Carruth is the sort of filmmaking magician that rarely ever comes around; he has the rigor and discipline of Stanley Kubrick and the heart of Terrence Malick. There's simply so much in every frame in Upstream Color that it almost seems reasonable that nine years passed between Primer and this. And while Primer is an absolutely phenomenal film (and often unthinkable that a first-timer helmed it), this is a perfection of Carruth's aesthetic, and he's only two films deep.
Upstream Color will be remembered because it's wholly unique and it trusts its viewer. It's easy to be cynical in an age of think-free reboots and sequels. For those reasons, Carruth is not just an excellent filmmaker; he's a necessary one.