The STN-J is called in by the local police when a dried corpse is found. When Robin finds a dead insect on the body the team goes on a hunt for a Witch who can control insects. They find that there were two previous victims found in the same condition. The cases point to a similar rash of deaths leading back hundreds of years. Apparently, all the dead are Witches. Is the STN-J dealing with an immortal who feeds on Witches?

As part of an STN-J a sting, Dogima and Robin take jobs as waitresses in Harry's bar. The man they're hunting was once betrayed to the STN-J by his own father, the owner of Harry's. As they wait for the prodigal son to return, the STN-J begin to realize that they're not the only ones after Yutaka Kobari.

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.

As Robin's powers grow, she wrestles with her old beliefs of what a Witch is. Meanwhile, Solomon Headquarters sends a powerful Hunter named Corneli after Robin. Will the secretive Amon help her this time, or will he allow Cornell to destroy her?

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.