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?

When Robin's Vespa runs out of gas during a rainstorm, she is picked up by a kind-hearted motorist. Shortly after dropping Robin off, the woman is killed in a horrible accident. Upset over her death, Robin senses that a Witch may have been involved. Together with Amon, Robin pushes forward to uncover the truth.

When a suspected thief's wrecked car is pulled from the harbor, the STN-J suspect there is more going on then a mere accident. When the go to question the suspect, however, he flees in his car, crushing Karasuma's vehicle with a powerful blow in the process. But, was it the thief doing the crushing or a more sinister force?

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.