WARNING: The following contains spoilers for Rust-Eater Bisco Season 1, Episode 5, "Children's Fortress," now streaming on Crunchyroll and Funimation.
Episode 5 of Rust-Eater Bisco opens with Bisco and Milo yet again in hot water. This time, they're butting heads with a rag-tag group of kids whose home might hold the answers to understanding just how corrupt a figure Governor Kurokawa really is. Both Pawoo's and Bisco and Milo's journeys beyond Imihama fill in crucial details of what caused Japan to crumble.
With their original plan to travel to Akita ruined, Bisco and Milo head through the Calvero Shellsand Sea on foot. Stumbling upon the outskirts of the pieced-together Testujin Town, they are confronted by gun-toting children. The wastelands leave much to be desired, so understandably, the kids think Bisco and Milo are there to ransack the village and take off. Since Bisco makes the situation worse by refusing to release Kousuke -- one of the kids -- he settles the scuffle by offering his bounty in exchange for meals.
Before they're restrained and taken inside the town, it's revealed that Bisco doesn't even know who Governor Kurokawa is. It's also said that the Governor likely secured his reelection by disappearing the other candidates. While Bisco is locked up with Kousuke standing guard, Milo is taken to a different location in the village, with the young girl Plum making sure he doesn't escape. She ends up removing his restraints, sensing no threat following his graciousness at the meal he's provided.
As he inquires about the lack of adults, Milo learns that the Imihama army led the people of Tetsujin Town to believe they were infected with the Rusting, not the much milder shellskin that Milo easily treats for the children. Kurokawa's lie drove the adults out to find work and afford treatment, forcing the kids to take up arms and fend off the flying blowfish that have attacked every year since. It's alluded to that these adults are the ones who comprise Kurokawa's rabbit mask-wearing special forces.
Meanwhile, Pawoo is in Shimotsuma being fed lies about the Mushroom Keepers. She happens upon a gruesome pile of corpses, only to then save an elderly couple from a giant spider. They inform Pawoo that the corpses are a decoy for bandits, while the rest of the town's population either died or fled not long after receiving treatment from a wandering Mushroom Keeper.
Supposedly, this Mushroom Keeper set up camp offering to treat anyone who was ill. As people showed signs of improvement, more and more came to see them -- until they all began to die from the Rusting. They say that, before leaving, the Mushroom Keeper told them the "experiment was worthwhile."
Though Rust-Eater Bisco has mentioned that not all Mushroom Keepers are good people, this story stands on shaky ground once the couple try to drug Pawoo and attack her. As it turns out, they were the bandits leaving corpses as decoys for unsuspecting travelers. Unfortunately, Pawoo doesn't get much else out of them before they set off a self-destruct explosion. While their story may have been entirely fabricated of their own volition -- or an extension of the lies Kurokawa's been spreading -- not everyone is so quick to believe Mushroom Keepers are at fault for the country's collapse.
Kousuke reveals that when he was younger, a Mushroom Keeper saved him from a deadly illness. Instead of fear, he has nothing but gratefulness and reverence for the Mushroom Keepers and their abilities. It's not long before the other denizens of Tetsujin Town, even stubborn leader Nuts, are left feeling similarly when the flying blowfish arrive for an out-of-season feeding.
In a show of endearing ignorance that is quickly becoming characteristic to Rust-Eater Bisco, Bisco tells Kousuke to recite the station names of the Keikyuu Benibashi Subway Line as he takes down each of the blowfish, refusing to admit he can't read kanji. It's possible that Bisco and Milo are now set to find the subway and get it running again toward Akita. Though, as Jabi is caught infiltrating Governor Kurokawa's forces, who's to say if the duo will have another sudden but crucial detour in the next episode.