Riko wakes up to find Reg asleep above her. He has used his extendable arms to make a large tripwire trap around them. Their current depth is 820 meters within the 1st layer, so far beyond Riko's former dream of reaching 400 meters that they cannot even see it. Encouraged, she thinks they will reach the bottom of The Abyss in no time. For breakfast, Reg catches some Demonfishes, which Riko uses to make Riko Soup. It looks bad to Reg, but tastes good.
Riko takes out her “Star Compass", but it slips out of her hand and disappears over a waterfall before Reg can grab it. Riko is sad, but quotes an old saying: "Everything taken from The Abyss will eventually return there, be it an object or a life." This reminds Reg about Leader's letter, which he finally gives to Riko. Inside is a fresh copy of Lyza's creature profiles, as well as a warning that Leader is already pursuing them. They immediately pack up and continue their descent. Riko believes that Leader is both supporting their quest and testing them, so they must reach the 2nd layer before he catches them in order to pass the test. They run into a Silkfang, but Reg manages to hold it off long enough for them to escape.
As they near the 2nd layer, Reg glimpses something and realizes that someone has caught up to them already. They try to flee, but are quickly blocked by the pursuer, who is revealed to be Hablog.
Riko and Reg are wary of Hablog, who seems happy to see them. He immediately picks up Reg to examine him, amazed that a treasure of The Abyss was right under his nose the whole time. Riko tries to subtly signal Reg to run when he can, but Reg hasn't learned hand signals. Noticing this, Hablog explains that he isn't there to capture them.
In a flashback, Shiggy and Nat visit Hablog at his home and beg him to escort Riko and Reg to the Seeker Camp in the 2nd layer. Shiggy convinces Habolg by adding it may be his only chance to see a treasure of the Abyss.
Hablog is prepared to keep his promise to guide Riko and Reg, but Riko refuses, because she doesn't want to cheat on Leader's test. Hablog gives them some medicine and steamed buns for the trip. He also mentions that Ozen is the White Whistle in charge of the Seeker Camp, as well as the same person who helped Lyza carry the infant Riko out of “The Abyss”. Riko is doubly excited to meet Ozen for those reasons, but Hablog warns her to be wary of Ozen, because painful things await Riko.
After parting with Hablog, Riko and Reg reach the 2nd layer, which means they have passed Leader's test. Reg recognizes that this does not mean they have escaped, but that they have left the human domain, and will now be escaping from non-human threats. Reg hears a voice weakly calling for help, and he and Riko rush to the scene. They find a bird-like creature standing over a fallen delver. Riko stops Reg from helping, realizing it is a trap: the creature is a Corpse-Weeper, which mimics the cries of its human victims to draw in more prey for its colony. It is soon confirmed that the delver is already dead. Suddenly, another Corpse-Weeper swoops in and grabs Riko, flying off with her. Reg prepares to get her back with his extending arm.
- Volume 2, Chapter 9: First Layer, Edge of the Abyss
- Volume 2, Chapter 10: Second Layer, The Forest of Temptation
references to previous episodes