第 5 集: Reg 在怪獸攻擊中穿梭，Riko 揭開 Iruburu 的黑暗歷史，並發現 Nanachi 被囚禁的真相。

5

Reg attempts to make his way back to the village, but gets lost and is attacked by monsters. He is saved by Faputa's robotic companion, who explains it is a robot called an Interference Unit, designed to collect data on the Abyss. Reg notes that he and the Interference Unit have similarities, but the Interference Unit admits it has no data on his model. It then guides Reg back to the village, which he says is called Iruburu. At the village, Riko has a brief conversation with Wazukyan, who she finds out is one of the Three Sages, the founders of Iruburu. She then decides to search a cave on the outskirts of the village that the Hollows are too scared to enter, hoping to find Reg and Nanachi in there. However, she instead comes across Vueko, who reveals she was imprisoned for trying to prevent the founding of Iruburu due to its dark origins. Seeing that Vueko can help her, Riko removes Vueko's bonds and has her guide her to Nanachi's location. Vueko leads Riko to Belaf's home, where Riko is shocked to discover that Nanachi traded her own freedom to Belaf to stop him from using Mitty as a food source. Belaf explains that in the past, Bondrewd visited Iruburu and brought Mitty with him. Belaf was so enamored with Mitty that he sacrificed a significant part of his body to create a perfect copy of her. Riko then asks Belaf how much it would cost to buy both Nanachi and Mitty's freedom, and Belaf replies that Riko would either have to give up both her eyes, both of her legs, or half of her intestines. (Source: Wikipedia)