While interviewing Lexie, Echika receives a report about the ongoing investigation. It only strengthens her suspicions towards Harold. Echika decides to get to the bottom of this case, but shortly after, something unexpected happens to her.

The time has come to reveal Harold's past. Once a wandering, lost Amicus, Harold was taken in by Sozon and began working alongside him as a detective. But then a gruesome case that would later be known as "The Nightmare of Petersburg” shook their world...

It seemed like the investigation had advanced after apprehending Furman, but instead the case ends up taking a new turn. After further deductions, Echika and Harold arrive at a place where…

The forces of evil hadn't stopped with the explosion at Totoki's apartment, they've also been creeping up on Echika. Once again, she finds herself in danger, and Harold takes on the taboo…

It's time for Harold and Echika to confront each other. Echika tries to reason with Harold, who's burning with the desire for revenge. In the end, Harold comes to a decision, and―

Echika, having realized Furman's true motives, discovers the shocking truth…and it's a huge secret involving Harold.

Harold and Bigga notice what all the victims from these attacks have in common from the message Echika left behind. They identify who and where the culprit is, and rush to rescue the abducted Echika, but…

The main suspect in a recent assault case turns out to be Harold. However, during Harold's interrogation, someone else attacks his flatmate, Darya. Echika "Brain Dives" into Darya's "Your Forma" where she sees the attacker's face—which is identical to Harold's.

After receiving an incomprehensible report from Totoki, Echika, and Harold head to the municipal police to find out the truth. It turns out that the report was about a phone call from someone who was never supposed to be able to reach them…

Cyber-Inspector Echika and Assistant-inspector Harold once again partner up. Thanks to Harold's strategy, the real villain has finally come to light, but behind the culprit lies an unexpected truth.

Echika and her team found the spot where E's followers meet up. Bigga, who's helping with the investigation, can't contain her shock when she sees a certain person there.

Echika and Harold grow more and more suspicious upon learning that Abaev was the one who received the digital clone requested by Elena. At the same time, another incident once again mimicking the "Nightmare" takes place. The victim this time turns out to be someone completely unexpected.

Echika feels uneasy from keeping the major secret about Harold. In the meantime, posts targeting the Cybercrime Investigation Department have been exposed on a message board.