This part revolves around a man called Ellasone. He's a person who creates magical restraining and containment devices for the Necessarius. One day, he suddenly disappeared, and if his knowledge leaks out, it could potentially lead to magicians escaping from the Tower of London. It's unknown whether he was brought away be some else, or disappeared on his own. Kanzaki was sent to find and bring him back.
At the start of the chapter, Kanzaki and Ellasone fought, but Ellasone escaped.
The next day, a messenger came to the jeans shop where Kanzaki was, and asked Kanzaki and the Jeans Shop Owner to help with the investigation. The Jeans Shop Owner is actually kind of like Kanzaki's "partner" and has knowledge about magic, although he's more like a volunteer. So Miss Tour Guide, Jeans Shop Owner and Kanzaki went to Ellasone's house.
There, they found a bunch of "devices" which were not sold to anyone, and the Jeans Shop Owner was asked to analyze them.
Also, they met a girl called Seachel, the one who noticed Ellasone's disappearance and reported it. Seachel was abandoned by her parents when she was 10 and also became a victim of child trafficking. She was saved and sent to an orphanage by Ellasone. Seachel wanted to pursue Ellasone in search of her purpose in life, and kept on escaping from the orphanage because of that. Eventually, Ellasone knew about it, brought her out of the orphanage, and let one of his neighbors take care of her.
After that, Seachel offered to help with Ellasone's work, but he refused. However, Ellasone eventually noticed Seachel's abilities to escape. Naturally, as a person who creates restraining and containment devices, this interests Ellasone. He also found out that Seachel escaped to search for her purpose in life. Eventually, Ellasone decided that the only way to keep Seachel safe is to give her a purpose in life and let her help with testing his creations. Since then, Seachel sees this job as something that she needs.
When Kanzaki and Jeans Shop Owner left Ellasone's house, they took a bunch of the devices away to analyze. The tour guide went to St. Julian's Cathedral to meet with the bishop there, since the bishop seems to be concerned about Ellasone's disappearance.
On the way back to the jeans shop, Kanzaki received a call regarding a Magical Organization that was in contact with Ellasone before his disappearance. Kanzaki went and fought them, but the organization didn't know anything.
Back in the jeans shop, they started analyzing the devices. The owner used a magic which allows him to see the "magical blueprint" of a device, and asked Kanzaki and the tour guide to do the same and split the work so that they could speed up the analyzing process. They noticed that each of those devices have Cathedral-level strength. Kanzaki then realized that those devices were actually miniatures of the St. Julian's Cathedral, and were made to mimic the security systems in that cathedral so that Ellasone could analyze them. They deduced that Ellasone's plan is to attack St. Julian's Cathedral.
Ellason easily infiltrated St. Julian's Cathedral, and was able to reverse trap the guards, since he already analyzed the security systems through the devices he created. He went straight to the bishop's room.
Meanwhile, Kanzaki came to the Cathedral. There, she encountered one of the tools created by Ellasone, in the form of the Gleipnir.
In the bishop's room, Ellasone restrained the bishop and interrogated him. The bishop is actually the one behind that child trafficking project. The purpose is to give a steady supply of magicians to the Necessarius. However, the child trafficking project is not supported by either the Necessarius or the Church of England. The bishop of St. Julian's Cathedral started the project himself so that he could become a good supplier and get more merit for himself. As Ellasone was killing the bishop, Kanzaki came into the room. Then, it was revealed that Ellasone knew about the bishop's project all along, even before he saved Seachel. He had planned to kill the bishop all along, but also hated himself for being a hypocrite and getting joy from being a hero and the "purpose of life" for one of the victims of the project. Because of that, he intended to kill himself to completely free Seachel.
In the end, Ellasone lost to Kanzaki, and was handed over to the Church for punishment.