Title: The Challengers 「???」 (???)
Japanese Date Aired: September 29th, 2017
The episode starts off with flashbacks of Reg's and Riko's adventures up to the ending of episode 12. We then see Nanachi dragging Reg back to her hut (Reg had fired his Incinerator in the previous episode's ending). We then start a flashback showing the early happenings of Nanachi and Mitty and how they got into their current position.
It starts with Nanachi at what seems to be an orphanage. Nanachi is lying down reading a book, thinking to herself. Children in the hallway outside her shared room leave to go outside, Nanachi follows. As they gather, Nanachi is wearing tattered cloths, a boy comments on her bad smell.
A white whistler, Bondrewd, stands in front of the children and explains to them he is a chief and tells them "I've come here in search of children suitable for forging a path to the netherworld's next era". He asks the brave children to step forward.
We see Nanachi looking into the abyss from a building in Orth that looks like Reg and Riko's old orphanage. Two kids are denying Mitty the chance to work with them. Our first look at normal girl Mitty shows she has long red hair and red eyes. She's topless and wears only a bra and loose underwear (most of the other children have the same outfit). Nanachi thinks to herself "So we're not the only ones, then, huh?".
In an unknown place, the children are gathered in front of a vessel to begin their descent. Bondrewd explains that they will be guided by other cave raiders and their descent is ~13 kilometers and that they will be at the bottom of the firth layer and that they will strive to unravel the final mysteries of this world.
During their descent the children wrap up in blankets, some even sleeping. Nanachi is eating bad food. Mitty and Nanachi have their first interaction. Mitty gets in Nanachi's face asking about Nanachi's ambitions, then immediately explaining her own (To be a White Whistle). Nanachi is annoyed. Nanachi explains she doesn't care what she does, as long as she came to the Abyss, and that before this, she dug food out of garbage to eat. Mitty explains of the treasures to find, the two agree to be partners.
The two read from a book called "Capital of the Unreturned", its written in nether glyphs, which Nanachi can read, but most can't. A monster can be heard outside the vessel the children are in, which scared them, but Nanachi looked generally unconcerned.
They arrive at they're destination. A voice of an intercom says that they will suffer the strains of ascending if they climb more than 10 meters. The children gather at the end of a tunnel to find a beacon, a beacon that looks similar to the one during the opening. They look and hold hands as Nanachi appears nervous. Bondrewd shows the children to their room.
Mitty asks about the "Abyss Faith". Nanachi explains "in a nutshell" "When a life is lost in the Abyss, the soul is said to return to the bottom of this planet and then the soul changes form and departs on a journey to someone who has wished for life". The pit replaces God and that its a comfort to cave raiders. Mitty praises Nanachi. Over time, Bondrewd comes back and asks for a child to come out until only Nanachi and Mitty are left. Mitty wishes for them to go out together. Mitty and Nanachi are sleeping together, Bondrewd calls for Mitty and tells Nanachi to be patient.
Nanachi sneaks out of the room and explores. She over hears a man and Bondrewd talk about how they are killing children is inhumane. Nanachi runs and searches for Mitty. Nanachi finds Mitty inside a clear cylindrical container. Bondrewd catches Nanachi and explains her perfect timing in that it's her "turn". Nanachi is placed inside another container by Mitty, Bondrewd explains that they are elevators that can go into the sixth layer quickly. The destination is a dead end, but is perfect for research on human subjects. The sixth layer's curse: "Death, or loss of one's humanity". The two are dropped into the depths. They land on a pile. Around them are mutants who have lost their humanity. Mitty assures Nanachi about her fate. They ascend. Nanachi turns into the present form Nanachi. On Mitty's side, she's bleeding and screams that it hurts. Nanachi expresses her friendship to Mitty as Mitty mutates. Mitty asks Nanachi to kill her.
Bondrewd opens the elevators and expresses his interest in Nanachi. Nanachi is distraught. Nanachi is drawing a crewd picture of Mitty. Bondrewd says that she should be helping with research. He says that Mitty lost her humanity, but also is incapable of dying. Bondrewd has tried to kill Mitty 9 times, but won't die as Mitty grows her limbs back.
Nanachi escapes with Mitty. Nanachi roams across a snowy land. Fast forward to Nanachi establishing her hut. Nanachi tries to kill Mitty many time to no success, but instead causes her suffering. A cave raider is bleeding and Nanachi takes him in. Nanachi is unable to save him, so she kills him and buries him.
After Reg wakes up (back to present), Nanachi explains he has the perfect weapon, that Mitty won't grow back with him using his Incinerator. She says that Mitty has totally lost her humanity and that her soul is imprisoned in her body. Reg asks to think about it. Nanachi apologizes for asking Reg to do such a thing. Reg contemplates if Nanachi will kill herself after he kills Mitty.
Mitty is chewing on Riko, Reg stares. Nanachi says she'll make a meal, Reg insists he does it. Reg fails at making anything good, it's worse than Nanachi's creations.
Reg is cleaning Riko. Nanachi is reading to Mitty. Mitty comes out of her place, Reg sees Nanachi asleep. Reg wonders if it's okay to leave Mitty alive.
Reg stands by Nanachi as she's fishing. He asks her if Mitty is unhappy. Nanachi predicts his next question of the necessity to kill Mitty. She explains that Mitty can live forever, Nanachi can't. She says when she dies, Mitty will be alone for eternity. If Mitty is stabbed, it hurts her, and she'll be forced to suffer forever. She asks again for Reg to kill Mitty. Reg asks for a promise that Nanachi not kill herself, Nanachi promises, Reg agrees to kill Mitty.
Nanachi sets Mitty outside in a pile of stuffed animals. She talks to Mitty. Reg prepares his weapon. As Reg's weapon charges, Nanachi calls for him to stop. She runs over to Mitty and cries over her one last time. She walks back and tells Reg to do it. Mitty is destroyed. She turns her back, not looking at Reg's work until he's done. Nanachi and Reg cry.
We see Riko's mother, telling Reg not to be sad, she offers him food. Reg wakes up. Riko is awake again. Riko provokes her hurt arm. Riko and Nanachi had been cooking. Nanachi asks Reg to stop Riko from rubbing her. Reg wants to join in. Riko makes a meal, Nanachi loves it, but pretends it to be okay. Riko asks aloud if someone else lives in Nanachi's hut, this shocks Reg and Nanachi into silence. Nanachi asks how she knew, Riko has to ask that herself. She then remembers a dream.
She explains she was in between two rocks. They keep squishing her with much pain. Riko says she didn't remember what she was or how to speak, that she was very scared and was crying. She then hears another girl crying and says she sounded scared. Riko/Mitty wanted to tell Nanachi that it would be alright. She smelled smoke and the crying had stopped. Riko says she could could see the girl and make out her profile. The girl turned her back to Riko. Riko says she looked like a cave raider. The girl is regular Mitty. Riko then remembers and then wakes up.
Reg explains that Riko was once dead. Reg tries to use this tie as an explanation. Nanachi says its alright.
The company leave to a hot lake. Reg helps undress Riko, the two get in. Riko notices Reg's (erect?) penis, Reg is heavily embarrassed. Nanachi refers to the time Reg blew air into Riko's lungs and spins it off as Reg kissing Riko, making Reg more embarrassed. Nanachi asks Mitty silently to wait for her a bit longer.
Nanachi and Reg are cutting off Riko's arm parasites (please edit this and put in what Nanachi said they were). Riko is in much pain. After the operation, Riko is trying to move her hand. She only is able to twitch her thumb. Reg moves in and apologizes to her for the whole situation. Reg and Riko fight to take the blame. Nanachi was listening a distance away, cringing. Riko asks Nanachi to come with Reg and Riko on their adventures.
The company release a message balloon and we see it's progress to Orth. They then go and prepare their things to leave. Nanachi looks back at her hut for the last time.
Lastly, Bondrewd surprised for Mitty's life signature has disappeared, he offers a gratitude to Nanachi and wishes to meet her again.
- Volume 3, Chapter 23: Dreadful Experimentation
- Volume 3, Chapter 24: Liberation of the Soul
- Volume 4, Chapter 25: Survive from Darkness
- Volume 4, Chapter 26: A New Start
- Nanachi and Mitty escaped from Idofront, the Forward Operating Base due to Bondrewd's dreadful experimentation
- Bondrewd (present)
- What's in the package?