Long after the serial killer cases connected by one named John Walker, the police continue to use the ID Well to jump into the psychie to find killers. Akihito and his partner, Hondocmachi, are sent into these ID Wells to solve the case. But in the wells they have different names and remember being brilliant detectives.

Akihito remembers being Sakaido, the Brilliant detective. Hondocmachi remembers being Miyo, the brilliant detective. They work together inside the ID Well while the rest of the special unit observes them if they die in the ID Well, they are extracted and sent back in.

The point, find out who murdered Kaeru. When finding this young woman, they remember their identities as Brilliant detectives and try to find the culprit.

Now they're trying to find out the next serial killer but instead, stumble upon an ID Well from particles that weren't from a serial killer.

---

Momoki: "Are we ready to send them into the ID Well?"

Sarina: "Yes, sir. Akihito and Hondocmachi are ready."

Mokoki: "Send them in."

The machines activated by the others in the room and the two were sent in. Once inside the ID Well, Akihito and Hondocmachi are now the Brilliant detectives Sakaido and Miyo. But they look around. Something felt off. They do find Kaeru. Dead with something unknown.

Sakaido: "Something feels off."

Miyo: "I know what you mean. But what is it?"

Sakaido: "Let's assess the situation before we look around."