This week, while waiting for Riko to heal, Nanachi teaches Reg the “true nature” of the abyss, calling it, essentially, a physical, if invisible, trap of barbs that are easy to descend through but quite difficult to ascend. The Abyss itself is both something that doesn’t want anything going in, but also won’t let anything that does get in get out easily, or without exacting a toll.
That toll would seem to extend all the way tot he surface, where lil’ Kiyui (Kiwi) has come down with an awful fever; a growing trend that is claiming lives. When Girou (Gilo) takes him off the island onto one of the ships of the “Caravan Fleet” docked there, he recovers immediately, without any medical treatment.
It would seem that all that was needed was to get further away from the Abyss.
And yet Riko, like her mother Lyza, her mentor Ouzen, and Nanachi and Mitty, couldn’t help but get closer and closer. The longing to reach thebottom of the netherworld and discover its secrets is far more agonizing than any trap, predator, poison, or curse. It’s a curse in and of itself; an infinitely seductive world beneath the surface, simultaneously beckoning and warning.
Good News: Mitty isn’t trying to eat Riko, she’s merely being friendly, and as Nanachi says, uncharacteristically “emotional” toward a visitor (though it’s doubtful they have many other visitors). She also points out Mitty was once a girl like Riko, then demonstrates to Reg how terrible her cooking ability is, prompting Reg to commit to cooking for RIko once she wakes up.
Meanwhile, Nanachi uses a thin, transparent “fog weave” to very effectively demonstrate the physical qualities of the Curse of Abyss; how it morphs to take the shape of whatever it covers, and the consequences of recklessly bursting through it.
Back in the hut, we’re “treated” to one of the more disturbing sequences in the show: Riko, covered in a fleshy film of her own, sits in the pitch black darkness but for a hole, through which Mitty’s eye peers. Riko peers back, and hears not the cooing and moaning of the present Mitty, but the more lucid cries of the girl Mitty once was. Chilling.
Continuing her lessons, Nanachi places a device in Reg’s helmet so she can communicate with him in real time from afar as he responds to a call for help from a Black Whistle, who then bristles when he sees a mere child has answered and begs him to flee.
Of course, Reg isn’t an ordinary kid, and he has a score to settle with this particular piercer, so with Nanachi’s aid he reaches out and grabs the curse, (which the piercer uses to predict the future with its red “nose”) and fires Incinerator at point-blank range, forcing the beast to shed 80% of its quills and withdraw.
Reg calmly asks the stunned Black Whistle to relay a message to Girou up at the Belchero Orphanage: “They are continuing their adventure.”
Even being almost killed won’t sate Riko’s longing to continue, and Reg knows that, so whenever she wakes up and is well and strong enough to do so, they’ll resume their descent. Reg, grateful for all of Nanachi’s help, asks if she’ll accompany him and Riko on their journey.
It’s not that Nanachi outright refuses their offer, but has a request of her own that is more pressing: she asks if Reg will kill Mitty for her. We heard through Riko the misery Mitty lives in each and every moment; almost gone but not gone enough for it to not matter.
Barring some kind of miracle that could save her, killing Mitty would seem to be a mercy; it’s just that after what happened with them and Bondrewed, Nanachi hasn’t been able to herself do what she know needed to be done. She hopes there’s enough emotional separation for Reg to do it instead.