After the most recent attacks, the Team keeps Robin under careful guard at the STN-J. The only one absent is Amon, who can't be reached. As they analyze the odd shell castings left from the attack at Robin's apartment, they find that only three people could have fired the Witch bullet at Robin. Unfortunately, the prime suspect has been dead for years. With growing uneasiness, they realize the only other person that could do this is someone very close to them all.

A new Hunter is killing Witches and placing origami cranes in his victims' hands with the word ""Robin"" on them. Robin decides to retrieve the Fragment from Nagira only to find that it's been stolen.

Suspicions about Zaizen's motives for Orbo leads Headquarters to cut funding by 40%. Nevertheless, Zaizen pushes ahead with his plan. Meanwhile, Robin and Nagira visit an old woman that was recently seen with Amon. When the woman is shocked to see Robin, they find out why; she has a photograph of a girl that resembles Robin in one of her bedrooms. Further investigations lead them closer to the truth behind Robin's past, as a link between genetics and Witches appears.

Zaizen is trying to develop a new type of Orbo that would allow ordinary humans to hunt Witches, but it has disturbing side effects. Amon meets with Robin but does not attack her; instead he reveals more about his orders. Dojima and Nagira follow a Factory assault van but the target is Sakaki!

With Karasuma captured by the Factory, the team mobilizes to rescue her from an uncertain faith. They secretly gather to form a plan for the dangerous mission, one where they must not only get past Zaizen's watchful eye and armed guards, but also navigate a labyrinth of rooms and corridors. As Robin works with the team, though, the Factory Researcher's words haunt her. Why did he call her the ""Devil's Child""?

Robin's mentor from Italy, Father Juliano, has made a sudden visit to Japan to see her. She confronts him about her real identity; who, or what, is she? Father Juliano gently revels to Robin her own true nature. Meanwhile, the STN-J Team and Nagira plan to stage an assault on the Factory.

Robin and Amon finally confront Zaizen and learn the truth about Robin's existence. To Zaizen's surprise, instead of being traumatized, Robin is instead strengthened with resolve. Now Robin and Amon must stop Zainzen's final solution for the sake of both Witches and Humans alike.