Rocks fall, everybody dies.
The episode starts with Milo’s near-death experience, followed quickly by a heartfelt scene between Milo (currently blind) and Bisco (Treating him with the anti-rust injection Pawoo gave him). They have a very good series of tender moments, including Bisco realizing what Jabi must have felt raising him, Milo saying that Bisco should date Pawoo, and the two of them talking about what it means to be partners and what death may have in store for them. Bisco promises to stay by Milo’s side as he sleeps, but of course immediately breaks that promise (among other lies, like the idea he’s treated himself) to go after Kurokawa.
We get more good villain mugging from Kurokawa, who tries to browbeat Jabi into joining his operation. It turns out that the “natural” Rust Wind has long lost its potency and rust cases are falling… or would be, except for the fact that to maintain his despotic control, Kurokawa has partially resurrected one of the terrible machines that first created the Rust, and with that and a giant pool of molten Rust has the ability to obliterate areas or spawn rust wind, keeping people sick so that access to medicine can keep them obedient. Jabi doesn’t cave easily to intimidation, and eventually it’s revealed that Bisco has replaced one of Kurokawa’s masked guards, allowing him to attack. Jabi and Bisco work it out so that Bisco will fight Kurokawa while Jabi shuts down his cannon, removing his ability to destroy either the valley with the Rust Eater or the village of the Mushroom Keepers as he threatened to do.
The struggle for the cannon is brief, with Pawoo showing up to help out and take out a dangerous gorilla. Bisco, meanwhile, fights through everything Kurokawa can throw at him… but not without cost as he gets an eye shot out early and ultimately starts to succumb to the rust, first fingers and then an entire arm shattering, having rusted to what appears to be stone. Even then, Bisco gets plenty of hits in, and both he and Kurokawa are limping badly. This isn’t a glorious battle, it’s a brutal test of endurance between two men who have chewed each other up but not been able to finish the job as they’re unreasonably tough, including as much as a chase moment with both the fleeing Kurokawa and pursuing Bisco limping badly.
Ultimately, when it seems like what’s left of Kurokawa might have it in the bag, a fully healed Milo shows up and shoots his arm off. What’s left of Bisco then rushes Kurokawa, and they both take a tumble into the molten Rust below. Even as he dies, Kurokawa rants and monologues, and Bisco pushes him down into the blazing metal, even as he sinks and burns himself. At the end, he says some last words to Milo, and asks Milo to finish him off so it won’t be the Rust that kills him. And, though in agony from it, Milo complies, putting one last arrow into Bisco’s heart.
Thus, we end the episode with our titular protagonist and our main villain stone dead. There are, I will remind you, three more episodes to the show. It’s actually quite surprising, and leaves me wondering… where we go from here. We were told there were other Rust Reactors that could be spreading the Rust, so I guess we might want to take those out as it seems like the world will heal more or less naturally without that in the way, but with Kurokawa dead I’m not sure what our opposition and struggle would be like. I could easily see one more episode, but three? It’s going to be interesting to see how we get another arc out of Sabikui Bisco with the Sabikui found and Bisco dead along with the antagonist.