In this episode, the series introduces a new infamous character, Jack the Ripper, whose presence leads Lupin to abandon a coveted diamond. But Jack's ambitions go even further: he drives the revival of Moriarty's gang, which is after a unique corpse made of monster tissue.

The episode also sheds light on Shinuchi's backstory. He unexpectedly survived a brutal experiment that granted him Onigami-like traits and escaped from the laboratory.

Tensions escalate in numerous confrontations. Shizuku and Carmilla engage in a thrilling battle full of skill and strategy. Carmilla, the vampire, uses her signature deadly kiss to gain an advantage. However, Shizuku manages to outwit her by using a cross as a weapon.

Meanwhile, Professor Moriarty's motives remain shrouded in darkness, but it is clear that he aims to create the perfect monster hybrid. To achieve this goal, he intends to capture werewolves.

The episode culminates in a battle where Shinuchi and Aya, previously considered the most powerful beings, are now challenged by Jack. Jack, a terrifying hybrid with the traits of a vampire, an Oni, and Aya's unique ability of immortality, is no easy opponent. In a surprising turn of events, Shinuchi manages to take the diamond from Jack.

However, the twist suggests that the diamond may not be the ultimate key. Shinuchi hints that Jack has already deciphered the diamond's secret code.